Added coveragerc file

Created by: stefanoborini

Adds the .coveragerc file for codecov execution.

.coveragerc

+[run]
+branch = True
+source = force_bdss
+omit = */tests/*
+       */bench/*
+       */scripts/*
+
+[report]
+# Regexes for lines to exclude from consideration
+exclude_lines =
+    # Have to re-enable the standard pragma
+    pragma: no cover
+
+    # Don't complain about missing debug-only code:
+    def __repr__
+
+    # Don't complain if tests don't hit defensive assertion code:
+    raise AssertionError
+    raise NotImplementedError
+
+    if __name__ == .__main__.:
+
+ignore_errors = True