As we are removing the s3 driver from source tree per change
I032b0fc16400cbd2112687d38e010128be699221 , it seems right to remove the
references of the same in the glance tree.
Updated here are files that referenced s3; these files include:
* documentation files
* documentation of the glance architecture (source and png files)
* config help text
* stores associated with location strategy
* tests
UpgradeImpact
Change-Id: I680ee2baf39b49156d173e2ae108ae5d0221eca7
Depends-On: I032b0fc16400cbd2112687d38e010128be699221
Depends-On: I5d2da0611365b838f41285b64cdcfef9adf50e85