Migrate tests from the Scala to the plain Java

[iushankin]

Rework all test to the Java with the TestNG framework

• add required dependencies to the pom.xml files
• swagger-core Migrate Scala tests for swagger-core module #1206
• swagger-jaxrs Migrate Scala tests for swagger-jaxrs module #1207
• swagger-jersey2-jaxrs Migrate Scala tests for swagger-jersey2-jaxrs module #1208
• swagger-hibernate-validations Migrate Scala tests for swagger-hibernate-validations module #1209

[webron]

Related to #804.

[webron]

This is not complete yet.