Ensure that the special 'all' environment is not case sensitive

Add tests for case sensitive 'all' environment check in all
languages, but it's only an issue with .NET implementation.
Merge pull request #54 from ResourceDataInc/case-insensitive-all-environment

Ensure that the special 'all' environment is not case sensitive
Deep merge implementation for C#

Only includes tests for public api features, not deep merge specifics.

http://antix.co.uk/Blog/Merging-objects-using-JSON.NET

https://github.com/JamesNK/Newtonsoft.Json/pull/94
Deep merge implementation for python

Only includes tests for public api features, not deep merge specifics.

http://www.xormedia.com/recursively-merge-dictionaries-in-python/
Deep merge implementation for ruby

Only includes tests for public api features, not deep merge specifics.
Merge pull request #56 from ResourceDataInc/deep-merge

Implement deep merge for environment configuration
Ignore .ruby-version
Ruby - Add `has_key?` method

Aliased as `include?`, as well as implements `respond_to_missing?`.
Python - Add `__contains__` method

My initial intention was to implement the `has_key` method, but the
Python 2 docs state

> `has_key()` is deprecated in favor of `key in d`.

Implementing `__contains__` allows the use of `in`, so I'm going with
that over the deprecated approach.

https://docs.python.org/2/library/stdtypes.html?highlight=has_key#dict.has_key
C# - Add `ContainsKey` method

I don't care for the use of exceptions as control flow, but I'll leave
it for now.
Ruby - refactor to use config instance variable
C# - Refactor to not use exceptions as control flow