Feature/GitHub workflow

[phibos]

Add a github workflow to run phpcs and phplint. The config has been adapted from other icingaweb2 modules.

Things done:

• convert all files to unix line endings
• fix long lines
• fix warnings and errors from phpcs and phplint

[phibos]

@Mikesch-mp Please feel free to contact me if you have any questions.

[phibos]

@Mikesch-mp are there any plans to merge this? If yes I can fix the merge conflicts and if not this request can be closed.

[phibos]

@Mikesch-mp are there any plans to merge this? If yes I can fix the merge conflicts and if not this request can be closed.

[phibos]

@Mikesch-mp if you are still interested in this CI pipeline I can rebase it or if you don't like it I can close the PR.

[Mikesch-mp]

Can you please redo it after i released 2.0.0?