make test non executable, otherwise nose skips it

when reading tempest run logs the following can currently be seen:

: INFO: Ignoring files matching ['^\\.', '^_', '^setup\\.py$']
nose.selector: INFO: .../test_endpoints.py is executable; skipped

chmod the files so they get run.

Change-Id: I5e3edb07eec7390877e9ac18b14974730e19088f
Merge "make test non executable, otherwise nose skips it"