Add information on setting up development environment, running tests and
generating documentation.
Also update .gitignore to list files that will be generated during
testing.
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
Previous test data was insufficient for proper testing.
Test compose runs and depsolving tests require precisely
set NVRs, dependencies, sub-packages, etc.
Using rpmfluff for these would be an overkill, it's better
to create RPMs directly from specs.