This prevents carrying hacks in the packaging specific to CI things
that will never actually land in Debian.
This will keep CI availability high while new packages are not yet
actually landed into Debian.
Since https://fwupd.github.io is now a thing, people can be directed there
rather than relying upon locally built documentation by default.
Also this will mean one less dependency to install for people who build
from source.
Lastly this finally means that I can do this set of actions without failure:
```
meson build
ninja -C build
ninja -C build install (PK prompts for password)
rm -rf build
```
Previously gtkdoc stuff was built as root due to the PK prompt and removing
it would lead to stuff like this:
```
rm: cannot remove 'build/docs/libfwupd/html/libfwupd-FwupdClient.html': Permission denied
```
For now this is happening on every master build, but in the future
after it's working reliably it should be restricted to only tagged
builds.
To accomplish this, swap a build from circlei and travisci that
will save docs to publish.
Building:
The Dockerfile really is just an intermediary file. While building it the
container can be built too all in one shot. No need to git ignore the
intermediary file any more as a result.
Running:
Dockerfiles support default entry points which means one docker command
can be used for starting all of them.
