Fix Docker files which had been forgotten in #594 and update scripts and docs to remove references to gb.
I also removed the `jenkins` directory which is outdated. We can revert f8d7e99 if we realise that it was a mistake to do so.
* Use absolute links in pull request template
Relative links don't work in most places
Signed-off-by: Aaron Raimist <aaron@raim.ist>
* Use matrix.to (for now) instead of linking to riot.im/develop
Signed-off-by: Aaron Raimist <aaron@raim.ist>
`gb test`s output is confusing as it is similar to that of `gb build`.
Rather than building, it's actually running all the tests. If no output
past this shows, then all tests have succeeded.
Updates CONTRIBUTING.md to include a note about this.
