Change user name limit to 255 characters

Origin user name limit in heat is 64 characters. but the max acceptable
username limit should be 255 in keystone.
This patch propose to change the limit to 255
Also, this can avoid warning from heat keystone client in heat
integration tests.
Closes-Bug: #1685817

Change-Id: I7b9e7076bd700c086b07f13dadf89531579aa4a1
1 file changed
tree: df6d45b2434f22fe95a91788406c3057f3e8c1ea
  1. api/
  2. common/
  3. functional/
  4. scenario/