Stop a bunch of test dependencies from being exported as real dependencies

Cannot start server with pac4j on classpath due to java.lang.IllegalStateException: Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError. See also http://www.slf4j.org/codes.html#log4jDelegationLoop for more details.
```pac4j-core``` is a true dependency, not only a test one. It should not be scoped with ```<scope>test</scope>```.