run-tests: move createhgrc() call into Test.run()
createhgrc() is an implementation detail of how tests are run. It makes
sense to move it into Test.run().
Note that this will cause the test execution time to include the
creation of hgrc. The author does not believe this is a significant
change worth worrying about.
try:
import coverage
getattr(coverage, 'process_startup', lambda: None)()
except ImportError:
pass