Test connectivity.

[ilatypov]

Exclude auto-generated tests as they do nothing.

Separate an integration test from the unit tests. This allows using "mvn verify" and a parameter file

src/it/resources/integration-test.properties

Allow running a single test directly with java,

java -cp target/ssc-restapi-client-2.0.jar:target/lib/*:target/test-classes \
    -Djavax.net.debug=all ListProjectsIT

Highlight authentication failures.

Fixes #5.