Reorder test cases

[sparre]

Finding failure causes may be easier if we keep the tests ordered with the simplest first and the more complex later on.

Some specific examples:

• Test that we actually have HTTP servers answering where we expect it from the test configuration (so we don't waste time wading through failed tests, which all are due to a single misconfiguration).
• Test AuthServer before we test any services using authentication.

[rostgaard]

Is this supported natively by py.test?