Remove unused config option auth_admin_prefix

The auth_admin_prefix was registered but never used. This change
removes it.

Change-Id: I22dd8454f10b79c57819e64bf0a274ce25b66d18
remove 8888 port in sample_data.sh

Swift now doesn't use 8888 port as any default service. And the origin
sample_data.sh always let new users to fail and modify swift bind port.
So switching 8888 port here to 8080 could generate sample data without
any change for building swift + keystone environment.

Closes-Bug: #1244304
Change-Id: If58f9f025f57565733aa25efc2fdf06865781391
Fixes tox coverage command

Change-Id: Id1816cca49989f5d38be285d9b2acca9ca6a2f56
Closes-Bug: #1245539
Merge "Remove unused config option auth_admin_prefix"
Merge "remove 8888 port in sample_data.sh"
Merge "Fixes tox coverage command"