Collections, Better Enums w/ Fewer exceptions

Introducing two new contributors, @mainstringargs & @Turkey2349

New Feature:

• Getting Collections (aka midlands)

Minor fixes & changes:

• Introduced interface RobinhoodEnum
  • All enums have been updated to contain a sample of their JSON representation in the API. Each enum can parse strings.

{ "time_in_force" : "gfd" }

TimeInForce.parse("gfd"); // = TimeInForce.GOOD_FOR_DAY

• AccountHolderInvestmentElement renamed to AccountHolderInvestmentProfile
• Cleaner exception handling in general
  • RobinhoodApiException simplified

Retrieving Options, JUnit, & Random Fixes

Welcoming our first contributor: @albanoj2 !

Unirest Patch, Exceptions & handling, GetFundimentalList, GetAllInstruments (singleton)

A big patch over Unirest, since the default httpClient is currently broken....ugh

An API can now get a normal List of every Instrument tracked by robinhood.

APIs can now use the GetAllInstruments method (which works as a singleton). This uses the paginated iterator in the background to load paginated results into a normal list

Lots of better javadocs

ApiMethod de-abstraction & Paginated Iterator

This release introduces 2 MAJOR changes/updates

1: More Specific control over ApiMethods & Unirest

UrlParameters & httpHeaderParameters were removed & replaced with String->String/Object HashMaps in ApiMethod (see here) and appropriate methods to modify them. The Request Manager was updated to use these new implementation.

2: Paginated Iterator & Iterable

Pagination is cool, but rather annoying to work with on the receiving end; so I made these:

The Paginated Iterator and Paginated Iterable have been completed. These will automatically send a GET request when the last list has been exhausted. Since the iterator has to make REST requests to function, their performance is functional but not very speeeedy!

Getting Orders & Instruments, more abstractions, exceptions, & documentation

v0.7.0-alpha

Some warnings about unfinished stuff