Add information about how the continuous integration is set up in Dendrite and how to run the tests locally so that people don't need to wait around for things to churn.
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I also removed the `jenkins` directory which is outdated.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.
