Umbrella feature requests for Neturon, Nova, Cinder

[slankka]

Issue description

Hi @olivergondza , I have made several PRs, please review when you have time.

It's divided into four PR:

Those changes are quite simple, except 230 which have been reviewed.

• https://github.com/openstack4j/openstack4j/pull/226
• https://github.com/openstack4j/openstack4j/pull/227
• https://github.com/openstack4j/openstack4j/pull/228
• https://github.com/openstack4j/openstack4j/pull/229
• https://github.com/openstack4j/openstack4j/pull/230

ConnectorNotFoundException occurs while run in IDE.

Solution for IDE

"Use classpath of module", example of "openstack4j-jersey2" https://github.com/ContainX/openstack4j/issues/832#issuecomment-283573338

Why hard to run tests for core-test using maven command line

• first of all, It's a little bit difficult to run mvn test in/for module core-test
  • core-test declaims skipTests=true in properties. No tests will run, and no class will be compiled while mvn test.
  • *Tests files are placed in src/main/java , it requires further unusual configurations, such as testSourceDirectory.
  • more reason for detail https://www.baeldung.com/maven-cant-find-junit-tests
• the core-test lacks of dependency 'openstack4j-xxxx'

Suggestion

• leave the code remain the same.
• or move the files to src/test/java and add one http connector dependency.