Allow concat to take non-array second parameters

Also improve and extend concat tests to lock down functionality
Supported Release 3.2.1

Summary
This is a supported release

Bugfixes
- Fixed `is_integer`/`is_float`/`is_numeric` for checking the value of
  arithmatic expressions.

Known bugs
* No known bugs
Merge pull request #227 from hunner/add_support

Supported Release 3.2.1
Patch metadata
Merge pull request #228 from hunner/fix_metadata

Patch metadata
Numerous changes to update testing gems.

This work updates a number of Gems to the latest versions (rspec,
rspec-puppet), and updates and tweaks a bunch of tests to work
with the updated gems.
Remove pry, whoops.
Ensure Gemfile retains facilities for Jenkins.
Remove this test.

It turns out that in 3.x the refresh functionality doesn't actually
exist yet, so testing it makes no sense.
Merge pull request #231 from apenney/32-testing

Numerous changes to update testing gems.
Merge branch '3.2.x' into 3.x
Merge branch '3.x' into 4.x
Merge branch '4.x'
(maint) Pin rake version to 10.1.0 for 1.8 compat
Merge branch 'maint/3.2.x-ruby-rake-1.8-compat' into 3.2.x
Merge branch '3.2.x' into 3.x
Merge branch '3.x' into 4.x
Merge branch '4.x'
Update README.markdown

Add code block for validate_slength.
Merge pull request #236 from PierreRambaud/patch-1

Update README.markdown