Reconfigure Travis CI for no virtualenv; #1081

Travis CI starts us off in a virtualenv, but we want to own the
virtualenv. I think it's actually a better experience for users if we
don't let them run bootstrap.py in another virtualenv, because it gives
us a chance to communicate Gittip's worldview on the matter (we're using
virtualenv as a library, not a cli). Let's see if we can convince Travis
to go along with us here.

.travis.yml

@@ -4,6 +4,7 @@ before_script:
  - echo "YES_PLEASE_DELETE_ALL_MY_DATA_VERY_OFTEN=Pretty please, with sugar on top." >> tests/env
  - echo "DATABASE_URL=postgres://postgres@localhost/gittip-test" >> tests/env
  - psql -U postgres -c 'CREATE DATABASE "gittip-test";'
+ - deactivate
  - make test-schema
 script: make test
 notifications: