Add a check to verify that the source distribution tarball that we
generate installs corrctly. It is useful to do this check as this is the
same tarball will be used when installing BuildStream via PyPI.

This check also happens indirectly in the coverage job where we install
BuildStream but this check makes it more explicit and will also cause
the CI to fail early if the tarball is not correct.

.gitlab-ci.yml: Verify that source tarball installs correctly

See merge request !720

tests/integration/source-determinism.py: Use cli_integration.

See merge request !715

This makes the integration tests use the same 'alpine' alias for the
tests as we use in the examples, this avoids a redundant download
of an extra alpine tarball in integration tests.

This is a part of #603

tests/integration/project: Use the same alias for the alpine tarball

See merge request !722

Chandan Singh authored Aug 23, 2018 and Tristan Van Berkom committed Aug 24, 2018

Add instructions to install and update BuildStream python package via
PyPI, and also make it the recommended method.

Part of #587.