Enforce full coverage for CloudPub

This commit enforces the full coverage for CloudPub as it's a
dependency for the `pubtool-marketplacesvm`.

Since the Pub and its related tools heavily rely on unit-tests it's
expected to have them enforced in 100%.

.coveragerc

@@ -1,6 +1,6 @@
 [report]
 show_missing = True
-fail_under = 90
+fail_under = 100
 exclude_lines =
     pragma: no cover
     if __name__ == .__main__.: