Upgrade org.slf4j:slf4j-api:1.7.2 to 1.7.12

Hi, I found two versions of library org.slf4j:slf4j-api in your project. It would be nice to keep the version consistency.

Their introduced path is:

1. org.apache.parquet:parquet-format:2.4.1-SNAPSHOT::null->org.slf4j:slf4j-api:1.7.2::compile
2. org.apache.parquet:parquet-format:2.4.1-SNAPSHOT::null->org.apache.thrift:libthrift:0.9.3::compile->org.slf4j:slf4j-api:1.7.12::compile

 Thanks!

Regards,

    Panda