Added custom exceptions.
Incorporated Try monads in caching code.
Added tests for cache implementations.

Still failing on concurrent implementation.
Fixed return value hell.
The Connector class will fulfill the functions that were planned for the Broker class.
Moved the cache producer parameter from the constructor to the get method.
Converted all source from 4-space to 2-space indent.
Renamed class type variables.
Minor cleanup.
More reformatting.
Added corporation requests.
Removed Ordered trait from ApiKey. (#3)
Parameterized the Await.result duration. (#2)
Added some EVE requests.
Added magnet-based ParameterMap builder.
Added magnet-based ParameterMap builder. (#5)
Merge branch 'feature/5_pmap_refactor' of https://github.com/mrogaski/sieve into feature/5_pmap_refactor
Completed conversion of char.Request to use ParameterMap. (#5)
Converted the remainder of Request classes to use ParameterMap. (#5)
Refactored the implementation of the parameterMap method on Request classes to use an immutable SortedMap. (#5)