test: fix test case name
test_requirements: remove Flask-Testing
helpers: added sign function

This function will be used to sign emails in the details webpage. If the
signature does not match between requests, it means that the email has
changed.
helpers: use sha1 for signature
app/gplus_register: include email signature in template context
all: fix pep8 issues
app/facebook_register: including email signatures in the context
app/github_register: include email signatures in template context
templates/confirmation: include signature in a hidden field