Upgrade to postgres 10.6

- use awx-python in shebang in dev env
  - scl enable where needed for rhel7 & container installs
  - use scram-sha-256 pg user hashing by default
  - ensure psycopg2 is using the correct PG_CONFIG at build time for the right libpq version

tools/docker-compose/awx-manage

@@ -1,4 +1,4 @@
-#!/venv/awx/bin/python
+#!/usr/bin/awx-python
 # EASY-INSTALL-ENTRY-SCRIPT: 'awx','console_scripts','awx-manage'
 import sys
 from pkg_resources import load_entry_point