Fixes the nightly builds

There were two errors in nightly builds:
1) We were mangling the INSTALL environment variable, which is used by dependencies in another context, causing our build errors.
2) Once this error was cleaned up, there was a formatting change in the way gtest lists tests that forced us to make some parsing changes in gen_test_list.py.

See http://submit-1.batlab.org/nmi/results/details?runID=249660, the linux test failure is due to an unrelated conda error that won't have any effect on the nightly and the fix is in another PR.