core.domain.exp_services_test takes 78.5 seconds on a fast laptop

[GoogleCodeExporter]

Perhaps this is a non-issue, but thought it may be valuable to flag 
core.domain.exp_services_test takes longer than most of the rest of the 
codebase combined. If there's an opportunity to improve runtime efficiency 
without sacrificing coverage it may be worth exploring.

What steps will reproduce the problem?
1. bash scripts/test.sh --test_target=core.domain.exp_services_test

Test output for reference:
15:32:54 FINISHED core.domain.exp_services_test: 78.5 secs
SUCCESS   core.domain.exp_services_test: 59 tests (77.5 secs)

Original issue reported on code.google.com by anu...@google.com on 15 Jun 2015 at 3:39

[GoogleCodeExporter]

Update: merging to the latest develop branch and running all backend tests I 
see a few take even longer than exp_services_test (e.g. 
core.domain.stats_domain_test and core.domain.stats_jobs_test at 143 secs each, 
core.domain.user_jobs_test at 132 secs, core.domain.subscription_services_test 
and core.domain.stats_services_test at 101 secs).

It appears one of the biggest speed bottlenecks across these tests is storing 
and retrieving from the AppEngine Datastore. Perhaps there's nothing we can do 
to accelerate this, but if there is it may be a way to reduce overall test 
timing significantly.

Original comment by anu...@google.com on 15 Jun 2015 at 8:24