not aborting if a single file to remove did not exist in appscale clean
added mocks in for when we start god with nohup
Merge pull request #298 from shatterednirvana/fixed-broken-god-mocks

added mocks in for when we start god with nohup
Merge remote-tracking branch 'org/testing' into better-error-handling-on-cleanup
Merge pull request #296 from shatterednirvana/better-error-handling-on-cleanup

not aborting if a single file to remove did not exist in appscale clean