Add changes link since last release to HISTORY
More reasonable to install with MediumSecurity
Faster Travis Builds with Caching

See http://about.travis-ci.org/docs/user/caching/

Use travis gem CLI to clear https://github.com/travis-ci/travis#cache

API ref https://api.travis-ci.com/docs/#/repos/:owner_name/:name/caches

h/t @moonglum https://github.com/hcking/hcking/blob/dd0c778a64c6478cdad89d14cda033551759312f/.travis.yml
This moves churn to use the gem directly opposed to using cmd line interface. This should simplify future changes and updates related to churn.

Added example configuration changes for churn to the .metrics file

Updated the default tmp directory to keep it under the metric_fu structure.

update tests and code.

various improvements and making churn integration a bit simpler

added history update

address some issues

remove unneeded line imporve test
Merge pull request #182 from danmayer/churn_api_interface

Run churn metric as library
Update how to run metric_fu on itself, add commit links
Add Pull Request links
Fix README.md code indentation.

[ci skip]
Merge pull request #187 from simi/patch-1

Fix README.md code indentation.
Add environmental variable to allow skipping gem cert
Extract gem deps via regex, rather than evaluating the gemspec

This should avoid issues relating to evaluating the gemspec and
  the underlying regular expressions should be fairly stable
Show version for activated gems