Switched to py.test for testing
Fixed travis issue with pytest.
Added multiple email tests.
Added multiple email tests.
Replaced obsoleted validators.Required with validators.DataRequired.
Minor change to Design goals docs.
Fixed macro render_checkbox_field to add 'checked' flag.
replaced is_enabled with active.
Merge branch 'master' of github.com:lingthio/Flask-User into user_invite
added UserInvitation class, cleaned up invitation logic