If pkg-config runs, but can not find the requested package, we still should log an error and add the default libraries to the list.
Merge pull request #780 from mdboom/setup/pkg-config-pkg-missing

Add default libraries to the list if the pkg-config lookup fails
This should fix #779. As @mdboom explained these equivalencies should be using the value of c (in m/s) as a scaling factor, but its units shouldn't really come into it. This should have been changed to c.value and h.value as part of #745.
Merge pull request #782 from eteq/fix-failing-open-file-test

Fix failing open file test
Merge pull request #779 from iguananaut/issue-779

Quantity throws an unrelated warning when converting through equivalencies?
turn off quiet on the travis scipy install, because travis times out