Increase test coverage

[danielhollas]

The current 55% is very nice, but perhaps we should aim higher before the 1.0 release.

Thanks @pzarabadip for enabling Codecov! 👍

[ezpzbz]

The main reason for this is the cclib parsers.
I need to go through them and see how we can fix this. Certainly something to keep in mind.

[danielhollas]

Good point. Perhaps adding more parser tests with various orca outputs is the way to go, with the new test suite it should be quite easy to add.

[ezpzbz]

@danielhollas Sure, we can have tests to cover the parser but I am not keen for this.
As discussed before, having cclib parser here is a short-term solution to have this plugin up and running. I am uneasy keeping it this way.
I am thinking of rewriting the parser to be native here and also more robust. There are so many hard-coded logics in the parsers such as if lines[x:y] that can easily break the parser if minor changes happen on ORCA side.
Also, orcaparser is very lengthy makes it hard to read and follow.

[danielhollas]

If you want to rewrite the parser, I'd say it's even more important to have the tests, otherwise it's going to be very hard not to break things.