Fix exception handling in heroku certs:*

Use exception handling for the File.read in certs:* which actually tells you which file read failed on a failure on posting to ssl_doctor.
Make pg:info twice as fast by doing calls in parallel
Show error when databas is not found
Merge pull request #1081 from will/pginfo

pg:info performance increase and dwh fix
Merge pull request #1080 from kainz/master

Fix exception handling in heroku certs:*