Fixes #19

This fixes bug #19 "pyramid.reload_templates setting does not work"

The bug appeared after the following commit https://github.com/Pylons/pyramid_mako/commit/3ed4f500a5d82a0f8fc4d914c978bb5e420ca704
I'm not sure I completely get how tests work, so I just reverted tests for MakoLookupTemplateRendererTests from previous revision. Let me know if I miss something, and I will update them.