Add PostgreSQL13 support

[benjaminguttmann-avtq]

For the blob I downloaded https://github.com/postgres/postgres/archive/refs/tags/REL_13_10.tar.gz

wget 'https://github.com/postgres/postgres/archive/refs/tags/REL_13_10.tar.gz'
tar xzf REL_13_10.tar.gz
mv postgres-REL_13_10/ postgresql-13.10
tar czf postgresql-13.10.tar.gz postgresql-13.10
bosh add-blob postgresql-13.10.tar.gz postgres/postgresql-13.10.tar.gz

For me compilation worked as well as migrating existing data from a deployment using v44.

Addresses #61

unfortunately I do not get the acceptance-tests running -.-

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/184685679

The labels on this github issue will be updated when the story is started.

[benjaminguttmann-avtq]

Close as the release has been updated