Fix test data, improve Makefile.

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.

tests/test_arch.py

@@ -9,10 +9,7 @@ import sys
 import tempfile
 import shutil
 
-here = sys.path[0]
-if here != '/usr/bin':
-    # Git checkout
-    sys.path[0] = os.path.dirname(here)
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
 from pungi.arch import *