Fixing range query, adding tests to support it.
Update docs reflecting refactor of DjangoMappingType

elasticutils.contrib.django.modles.DjangoMappingType turned into
elasticutils.contrib.django.MappingType
Spacing, line length. The test data at line 72 triggered some OCD that I didn't know I had.
Merge pull request #150 from theonion/master

Fixing range queries (__gte, __gt, etc)
Add Chris to CONTRIBUTORS
Merge pull request #151 from emidln/master

Updated docs reflecting refactor of DjangoMappingType
Fix two more errant DjangoMappingTypes in the docs
Add Brandon to CONTRIBUTORS
Update pyelasticsearch requirements to 0.4

It was in requirements.txt already, but needed to be reflected elsewhere.
Remove PYELASTICSEARCH_VERSION

This doesn't need to be in ElasticUtils. Users can import pyelasticsearch
to find the version.
Update CHANGELOG
ElasticSearch vs. Elasticsearch
Add more resource links
Cosmetic: Docs tweaks
Update contributor setup docs
Remove requirements.txt file

This nixes the unneeded requirements.txt file. The requirements
are already in setup.py.
Fix up tests

* added tests for functionality that wasn't tested according to
  coverage
* fixed some bugs I found along the way
* tweaked some tests for better maintainability
Add .coverage to ignored files
Change test settings so we use in-memory db
Documentation overhaul

* cleaned some things up
* moved some things around
* did the hokey-pokey