* Move testing logic from travis.yml to tests-ci.sh script
This way we can share this logic between travis CI and other systems
like for example a docker container.
* Move logic to create a testing environment to tests-environment.sh
As with the logic to execute the tests, this way we can share this logic
with other systems to tests linuxdeployqt.
* Install Qt also in tests-environment.sh
No reason to keep it separate from the rest as far as I know
* Wait until the X server is up and running
Otherwise we get into a racy situation.
* Add Dockerfile to create a testing container
This container tries to emulate the environment we have in travis-ci,
this way we can test whatever is failing on the CI locally.
Àlex Fiestas