tests: Adjusted test folder structure to roughly match skylines package
requirements: Replaced nosetests by py.test
tests: Fixed test_gjslint.py
tests: Fixed model tests
tests: Fixed functional tests
tests: Renamed TestTable class to ExampleTable

This was confusing the test runner
tests: Removed nose imports
setup.py: Use PyTest runner for "python setup.py test"
test_i18n: Improved test yielding and error messages
tests: Fixed flake8 issues

mostly import cleanups
tests: Added tests folder to flake8 checks
test_flake8: Run flake8 for each folder separately
requirements: Update pytest to v2.5.0
Merge pull request #216 from Turbo87/tests

Replaced nosetests by pytest
Travis: Generate assets before running tests
Fix database connection leak in tests

Without this, each flask app created in tests will hold
one database connection until all tests are finished. This may result
in test failure if database limits number of concurrent connections.
Implement py.test fixtures for database and flask application

Allows to set up database schema only once per test run, yet providing
clean environment for each test. Also, easier to use and reduces
setup/teardown code duplication in tests.

Reduces test time by ~50%.
Merge pull request #220 from kedder/for-upstream

Improve testing framework
setup.py: Removed Flask-DebugToolbar package from dependencies
tests: Removed outdated comments in test_authentication