Rust: fix lint/clippy errors and warnings

 error: question mark operator is useless here
   --> src/ser.rs:378:9
    |
378 |         Ok(ser::SerializeSeq::end(self)?)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `ser::SerializeSeq::end(self)`
    |
    = note: `-D clippy::needless-question-mark` implied by `-D clippy::all`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_question_markerror: called `is_none()` after searching an `Iterator` with `find`
  --> src/schema_compatibility.rs:99:32
   |
99 |                         return w_symbols.iter().find(|e| !r_symbols.contains(e)).is_none();
   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `!_.any()` instead: `!w_symbols.iter().any(|e| !r_symbols.contains(e))`
   |
   = note: `-D clippy::search-is-some` implied by `-D clippy::all`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#search_is_someerror: aborting due to 2 previous errorserror: could not compile `avro-rs`


error: used `assert_eq!` with a literal bool
   --> src/ser.rs:795:9
    |
795 |         assert_eq!(to_value(test).is_err(), true);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
    |
    = note: `-D clippy::bool-assert-comparison` implied by `-D clippy::all`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:600:9
    |
600 | /         assert_eq!(
601 | |             SchemaCompatibility::can_read(&reader_schema, &writer_schema()),
602 | |             false
603 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:620:9
    |
620 | /         assert_eq!(
621 | |             SchemaCompatibility::can_read(&reader_schema, &writer_schema()),
622 | |             false
623 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:662:9
    |
662 | /         assert_eq!(
663 | |             SchemaCompatibility::can_read(&reader_schema, &writer_schema()),
664 | |             false
665 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:679:9
    |
679 | /         assert_eq!(
680 | |             SchemaCompatibility::can_read(&writer_schema(), &reader_schema),
681 | |             false
682 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:683:9
    |
683 | /         assert_eq!(
684 | |             SchemaCompatibility::can_read(&reader_schema, &writer_schema()),
685 | |             false
686 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:698:9
    |
698 | /         assert_eq!(
699 | |             SchemaCompatibility::can_read(&string_array_schema(), &invalid_reader),
700 | |             false
701 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:711:9
    |
711 | /         assert_eq!(
712 | |             SchemaCompatibility::can_read(&Schema::Int, &Schema::String),
713 | |             false
714 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:723:9
    |
723 | /         assert_eq!(
724 | |             SchemaCompatibility::can_read(&union_writer, &union_reader),
725 | |             false
726 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:750:9
    |
750 | /         assert_eq!(
751 | |             SchemaCompatibility::can_read(&string_schema, &int_schema),
752 | |             false
753 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:767:9
    |
767 | /         assert_eq!(
768 | |             SchemaCompatibility::can_read(&enum_schema2, &enum_schema1),
769 | |             false
770 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: used `assert_eq!` with a literal bool
   --> src/schema_compatibility.rs:847:9
    |
847 | /         assert_eq!(
848 | |             SchemaCompatibility::can_read(&point_2d_fullname_schema(), &read_schema),
849 | |             false
850 | |         );
    | |__________^ help: replace it with: `assert!(..)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparisonerror: called `is_none()` after searching an `Iterator` with `find`
  --> src/schema_compatibility.rs:99:32
   |
99 |                         return w_symbols.iter().find(|e| !r_symbols.contains(e)).is_none();
   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `!_.any()` instead: `!w_symbols.iter().any(|e| !r_symbols.contains(e))`
   |
   = note: `-D clippy::search-is-some` implied by `-D clippy::all`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#search_is_someerror: aborting due to previous errorerror: could not compile `avro-rs`To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: aborting due to 12 previous errorserror: build failed