Bamboo server can be set for tests

Use `TEST_BAMBOO_URL="http://localhost:8080" nosetests` to forward the tests to a local installation.

Some tests are still taregtting the bamboo.io server intentionally. It is possible to change it (while offline) using:
`DEFAULT_BAMBOO_URL="http://localhost:8080" TEST_BAMBOO_URL="http://localhost:8080" nosetests`