Log Message:
py-test: updated to 3.7.4

pytest 3.7.4:

Bug Fixes
- Fix possible infinite recursion when writing .pyc files.
- Cache plugin now obeys the -q flag when --last-failed and --failed-first flags \ 
are used.
- Fix bad console output when using console_output_style=classic.
- Fix macOS specific code using capturemanager plugin in doctests.