Fix issue 30
stunnel connection to RDS crashes after going idle

https://github.com/heroku/heroku-buildpack-pgbouncer/issues/30

Trying suggestion from thread in issue.
http://www.helveticode.com/rds-postgresql-with-stunnel/
https://forums.aws.amazon.com/message.jspa?messageID=505895
enable via environment variable
ENABLE_STUNNEL_AMAZON_RDS_FIX=1

otherwise, do not set this option
tweak environment variable in script
ENABLE_STUNNEL_AMAZON_RDS_FIX
tweak environment variable in script
ENABLE_STUNNEL_AMAZON_RDS_FIX
tweak environment variable in script
ENABLE_STUNNEL_AMAZON_RDS_FIX
tweak environment variable in script
ENABLE_STUNNEL_AMAZON_RDS_FIX
add readme details for ENABLE_STUNNEL_AMAZON_RDS_FIX
Merge pull request #43 from edwardotis/fix_stunnel_idle_dyno_crash

Adds 'no_ticket' option for RDS reconnection fix