Convert to requests-mock

We've had some trouble with httpretty in the past and so are moving to
requests-mock. There should be no functionality change in this patch,
simply a transition to a newer library.

Examples: 
 - Python 2/3 inconsistencies
 - Breaking compatibility between releases
 - Incorrect package dependency specifications
 - Problems with distro packaging around tests 
 - *can* introduce a maintained state between tests.

Change-Id: I666a5c7e6747f0c5c2dc96336774fd0fcd3f5907
Use adapter from keystoneclient

SessionClient is mostly common code that wasn't yet released in
keystoneclient. Now that 0.10 is released we should use the adapter from
there as much as possible.

Change-Id: Ief6cd7e752fd8c9e9157364f99e270da7faff074
Merge "Convert to requests-mock"
Fix listing of flavor-list (V1_1) to display swap value

Current version of flavor-list(v1_1 API) does not show
swap value because of selecting wrong field name. This
change displays swap value in the same way to v3 API

Closes-Bug: 1354546
Change-Id: I5c8fca8207032814b96b8410213bf58209d9b526
Merge "Use adapter from keystoneclient"
Merge "Fix listing of flavor-list (V1_1) to display swap value"
Updated from global requirements

Change-Id: I1155f67196b5a8393ff53361ac9c63f3f7c23ad0