Filtering of attributes of the queried resources

[wallner]

This pull request adds the option of filtering of the attributes of the resources returned by queries.

Resolves #220

[tkrille]

I think you forgot to extend the methods for groups in org.osiam.client.OsiamConnector with the attributes argument.

[tkrille]

Please, also update the changelog.

[tkrille]

Please, also update the missing part in the release announcement.

[tkrille]

When do you think, are you able to write some ITs?

[wallner]

I'm going to write two ITs once this is merged.

[tkrille]

Please fix the last 4 comments and then this is ready to go.

[tkrille]

The Circle CI build is failing, but I cannot rebuild it, because it's contained in your private user namespace. Did you connect your fork with Circle CI? If so, please remove your fork from Circle CI, so that your PRs build under the OSIAM namespace again.

[tkrille]

I cannot build, license headers are missing for src/main/java/org/osiam/client/OsiamConnector.java:

$ mvn clean test
…
[INFO] 
[INFO] --- license-maven-plugin:2.11:check (default) @ connector4java ---
[INFO] Checking licenses...
[WARNING] Missing header in: /home/thomas/Source/Osiam/connector4java/src/main/java/org/osiam/client/OsiamConnector.java
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
…

Did you remove them?!

[tkrille]

Oh, auto formatter treated it like a javadoc comment, the old problem :(

[tkrille]

Thank you very much.