* Use Flask-Assets to minify self-hosted JS files
By having Flask-Assets minify the two JS files we ship, namely
main.js and bootstrap-select.js, we can shave off 28406 bytes.
The minified files are generated on startup. If one wishes to
manually clean them up or build them, they can use the
"flask assets" management command, e.g. "flask assets clean".
* Workaround to fix tests
State carries over in tests, which is the dumbest shit ever. Fix it
by clearing the bundles before setting them.
* Replace all `from nyaa import app` imports with `app = flask.current_app` (or `from flask import current_app as app` where possible)
* Add a separate config object for top-level and class statements as `nyaa.extensions.config`
Required because those codes don't have app context at the time of evaluation/execution.
* Remove `routes.py` file and register all blueprints in `nyaa/__init__.py`
* Refactor `nyaa/__init__.py` into an app factory
* Update tools
* Update tests (temporary, will be replaced)
* Update isort settings
* Apply import sorting (isort) on all files in nyaa/
* Fixed Flake8 errors in nyaa/ (see PR for list)
* Add isort to lint.sh and requirements.txt