Only print partial summary of missed coverage.

Author: ioquatix

.travis.yml

@@ -18,7 +18,7 @@ matrix:
     - rvm: 2.6
     - rvm: 2.7
     - rvm: 2.6
-      env: COVERAGE=Summary,Coveralls
+      env: COVERAGE=PartialSummary,Coveralls
     - rvm: truffleruby
     - rvm: jruby-head
       env: JRUBY_OPTS="--debug -X+O"