Reduce coverage report

A lengthy coverage report were most files are 100% aren't easy to read.
Adding the respective options in `.coveragerc` leads to a condensed
form.

Author: tomschr

.coveragerc

@@ -7,6 +7,11 @@ omit =
 
 [report]
 precision = 1
+fail_under = 90.0
+# Sort the report by missing coverage, descending
+sort = -Cover
+#
+skip_covered = true
 exclude_lines =
    pragma: no cover
    raise NotImplementedError