Covimerage

Fixes

- Fix map_function for invalid/unmatched "Defined" (73, 74)

Misc

- Use pipes.quote with Python 2.7 (72)
- Use flake8 built-in per-file-ignores

Changes

- Consider continued lines as executable (68)

Misc

- Cleanup tests and fixtures.
- Remove Function.calls (62)
- Support coveragepy 5 (alpha) (54)

Makes use of new information provided by Vim v8.1.0365.