app: added /signup route

This view will save the user in the database using data from the index
form.
templates/index: send form data to the proper url
Makefile: enable coverage report
tests: don't touch the database on FacebookLoginTestCase tests
tests: don't touch the database on GithubLoginTestCase tests
test_requirements: add coverage
test: don't touch the database on GplusLoginTestCase tests
test: fix SurveyTestCase.setUpClass
makefile: use gunicorn to run app in development mode
test: added test for get_locale function

Trying to increase test coverage.
Makefile: require 95% of code coverage

This is our current code coverage. I'm not going to increase it to 100%
now.
test: fix flake8 issues