Add coverage file

.coveragerc

@@ -0,0 +1,15 @@
+[report]
+include =
+    */account-financial-tools/*
+
+omit =
+    */tests/*
+    *__init__.py
+
+# Regexes for lines to exclude from consideration
+exclude_lines =
+    # Have to re-enable the standard pragma
+    pragma: no cover
+
+    # Don't complain about null context checking
+    if context is None: