EntityTypeParser ignores @Transient annotation on enum fields

[chrisribble]

com.datastax.driver.mapping.EntityTypeParser ignores @javax.persist.Transient annotations on enum fields and tries to load/persist them anyway.

Looking at the code, I don't think this was intentional; it looks like it's just a logic error. I'll submit a patch shortly with a fix after I finish testing.

[chrisribble]

My use case works with the changes from #78 (mark an enum as @transient to avoid attempting to load/persist the field). I also ran the tests and all of the tests in EntityTypeParserTest.java pass,

About half of the tests in MappingSessionAsyncTest failed, but they seem to fail without my changes as well; I'm going to chalk that up to my inexperience with Maven and/or something different about the version of Cassandra that I'm using or something.