Return ResourceList object instead of list in API

[polyatail]

This pull request addresses #40:

• Adds a new object type, ResourceList, that emulates a list but passes actions performed on items along to the underlying Resource object.
• Implements insert, append, extend, pop, remove, count, setting/getting/deleting by index
• Explicitly disallows non-equivalence comparisons (e.g., greater than or less than) in ResourceList and objects derived from OneCodexBase
• Tests list emulation and comparisons in test_api_models

[coveralls]

Coverage decreased (-0.09%) to 83.977% when pulling 191d352 on roo-apilist into a4b9eb4 on master.