Re: [cctbxbb] Tidy up CCTBX

Hi Graeme,

Turns out that the assert that libtbx has no dependencies is not strictly true:

if (not libtbx.env.has_module(name="phenix")): print "phenix module not available: skipping advanced tests" return

This is optional dependency (cctbx optionally uses Phenix for testing in various places) and doesn't cause problems. If you'd like to do disentangling, dxtbx-iotbx would be a good starting point as it really causes problems.