several improvement and fixes:
-report-summary-merged-prs allows to set a custom repository location.
-it shows the results for builds and unit tests in different bars.
-it reports builds as passed, error, or warning
-it reports unit tests as passed, error, or unknown
-when a release didn't change between the analized tags, it looks
 for all the tags that have not changed until the end tag.
Merge pull request #37 from nclopezo/use-own-repo-copy-2

Several improvement and fixes.