refactor CassandraCell, fixed cassandra test
Merge branch 'develop' of github.com:Stratio/stratio-deep into develop

Conflicts:
	deep-core/src/test/java/com/stratio/deep/core/extractor/ExtractorTest.java
	deep-elasticsearch/src/test/java/com/stratio/es/ESEntityRDDFT.java
Merge branch 'develop' of https://github.com/Stratio/deep-spark into develop
Fixed for new tests.