jose-jwt dependencies cleanup (3.x)

The project jose-jwt depends on:

• org.jboss.resteasy:resteasy-jackson-provider: Jackson 1.9.13 was released on July 2013 and is now legacy. Please, migrate to org.jboss.resteasy:resteasy-jackson2-provider. More over this dependency is only used in class JsonSerialization, and hence can be marked as <scope>optional</scope>.
• org.codehaus.jackson:jackson-xc: perhaps can be removed or marked as <scope>runtime</scope>.
• org.jboss.logging:jboss-logging-processor: perhaps can be removed or marked as <scope>runtime</scope>.
• junit:junit: should be <scope>test</scope>.