This is getting ridiculous. The test that used to fail on GHC 7.10 and
work on GHC 7.8, now failed on GHC 7.8 and worked on GHC 7.10.
It's better to have a predictable test suite with two less unit tests
than having an unpredictable one.
Currently PostgreSQL is dying on GHC 7.10 but not on GHC 7.8.
Hypothesis: The files left over from the acid-state local storage test
are consuming resources that PostgreSQL needs. These files are not
created on GHC 7.8, only on GHC 7.10.
The persistent test is failing and I have no idea why, as it's not
displaying any error message. This commit changes a few things with
PostgreSQL just to see if they make any difference.
Note that the persistent test suite passes with flying colors both
before and after this commit on my machine using PostgreSQL 9.4.2.
