rearrange regions info container

Now able to easily get the master and secondaries

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
set the region is_master field

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3tests: some more multiregion changes

Now creating a connection per region for each user, can access
master and secondaries, and set a default region.
No longer using a specific region per user, as it doesn't
make sense.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3tests: test_region_bucket_create_secondary_access_master

first multi-region test

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3tests: basic test to copy object between regions

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>