Some test plumbing

.coveragerc

 [run]
 omit = yird/[a_][p_][pi]*.py
+include = tests/

.gitignore

 .pytest_cache
 yird/static/*.css
 yird/static/*.js
+.coverage

Pipfile

 
 [requires]
 python_version = "3.7"
+
+[scripts]
+test = "pytest --cov-config .coveragerc --cov=yird tests"