[ci skip] Implemented getting array of strings of entities.
[ci skip] Implemented specific entity retrieval from id or name
[ci skip] Added new class definition for post and put calls assistance. Helps with JSON generation
[ci skip] Implemented creation of entities (POST).
Implemented deletion of entities (DELETE).
[ci skip] Made check to make sure ID parameter exists for creating entity
[ci skip] Implemented the ability to update entities given the ID (PUT).
Implemented deletion and creation of values for a given entity (DELETE) (POST).
Change the creation of values to specifically only use a BodyJson class object.
Implemented addition and deltion of expressions (POST) (DELETE)
Include more ruby versions for travis and fix specs specifically for getting entities.
Require OpenStruct library and change travis to not include  1.8.7
Change implementation of BodyJson to not use to_h in inherited class as it is not defined in ruby version 1.9.3