Separation of tests by folders and gate-docs fix

For unittests was created new directory and all such tests were moved
there. Also, .testr.conf was edited, where directory
magnetodb/tests/unittests' was set by default tox executing.

'tests.unittests.api.test_boto' and 'storage.model' were edited to back
compatibility with Python 2.6 and README.rst was updated with actual
values (stackforge) as well.

Also, 'sphinx' support was added.

Change-Id: I5d182644f692f4ca874185139cb72990040215eb
Closes-Bug: #1287144
Closes-Bug: #1287187
Test discovering logic fixed

Default discovering folder set to magnetodb/tests
default tox filter set to magnetodb/tests/unittests

Change-Id: Ic1445603eb4fcc476d1b3d2ee72c13307ebaebcc
Fixing a couple spelling mistakes

Change-Id: I46cc5f2689862c25680700495ca5721518e16890
Merge "Test discovering logic fixed"
Timeouts for cassandra storage backend tests increased

Some changes merged from new python driver release

Closes-Bug: #1288725

Change-Id: I883c24b7f56b11d586eb7d307444396a2d5aae05
Fixes tempest tests to fit DynamoDB API

Adds ResourseInUseException for duplicate table creating.
Changes logic of verifying exception messages and error codes.

Partially implements: bp tempest-dynamo-db-api-fit
Change-Id: I7dace4e3f584188fda02755304c08a460c46e07c
Merge "Fixes tempest tests to fit DynamoDB API"