Seed wiki db with random sample from test2wiki revision, page and user entries

Change-Id: Ic91716e76d63fe2ec9045fd4909fa84111c8c976
Create path using os.join.path instead of ''.join

Change-Id: I7138b6d2ca038cbb04c12e8c3a8c6494c1d75845
Fix create_account script by properly loading modules

Change-Id: Ife08aca4965916699bda09deca1c115c25ce66bc
Merge branch 'master' of ssh://gerrit.wikimedia.org:29418/analytics/user-metrics