Generalize list of supported metrics, add tests
Moved table.py to tables.py
Moved configuration.py to common.py
Moved some constants from tables.py to common.py
Add coverage report option to tox
Move some tests to a separate class
Use tuples to represent rows in the matrix
Fix minor error in param check
Add parameter syntax check test
Add tests for UserMetricsTable
Fixed occasional KeyError with unknown users
Added more tests for UserMetricsTable