Improve code quality

[yukiisbored]

The code quality of loklak_server has been pretty bad lately due to legacy choices and no enforcement for quality. I know that Loklak already have codacy but it doesn't enforce or set clear goals for the code quality.

This will be a really long issue and it's possible to tackle this in one move, here's a long plan I'm proposing to improve the code quality:

1. Setup a base coala configuration with every linters (bears) needed with configuration that will pass with the current codebase
2. From there we can start eliminating the ignores and lower the values slowly one-by-one and hopefully go to our goal in the end.

Of course, something like this won't work without co-operation from every contributors and developers, I'm hoping the following:

1. Nobody will negate the coala error code. (e.g coala --ci | true)
2. Nobody will increase the threshold and reduce quailty just to get it merged
3. Nobody will ignore the coala reports and leave this red
4. Nobody will merge PRs with red builds

I know this is really hard and pretty harsh but I hope that everyone will cooperate and together we can improve the code quality and make this project friendlier for new contributors.

[vibhcool]

@yukiisbored , We can add hacking.md and write down rules in it about syntax and conventions that shall be followed in addition to coala