Added marks for tests to allow testing in packaging

This PR introduces marks for all test functions, declaring all of the existing functions as remote, and adding a few new local tests. The EL7 and Debian packaging has then been modified to only run the local tests during build.

This enables some half-decent testing to be done during the packaging, which is nice, and should enable easier distinction between internal failures, and upstream changes from GWOSC.

This replaces #23, which was opened from the wrong fork.