Creates Cassandra column family with BytesType for column value validator (and comparators), instead of UTF8Type

Currently, if a column family does not exist, it is created by CassandraClient with CassandraMapping
but its column value validator and its comparators are UTF8Type, and it may cause an exception,
depending on its value as follows:

Column Families:
ColumnFamily: f
Key Validation Class: org.apache.cassandra.db.marshal.BytesType
Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
GC grace seconds: 0
Compaction min/max thresholds: 4/32
Read repair chance: 0.0
DC Local Read repair chance: 0.0
Replicate on write: false
Caching: KEYS_ONLY
Bloom Filter FP chance: default
Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
Compression Options:
sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor

me.prettyprint.hector.api.exceptions.HInvalidRequestException: InvalidRequestException(why:(String didn't validate.) [aarpdaily][f][ts] failed validation)
at me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:52)
at me.prettyprint.cassandra.service.KeyspaceServiceImpl$1.execute(KeyspaceServiceImpl.java:97)
...

It should be BytesType instead of UTF8Type to support any value.