Downgrade psycopg2 due to OpenSSL inconsistency

The wheel package for `psycopg2` is not compatible with the Python `ssl`
module due to their dependency on different versions of OpenSSL (the
wheel packages its own version, while `ssl` uses the system version).

Attempts to resolve by installing the dependency from source proved
challenging because we install `psycopg2` via Ansible
(`postgresql-support`) in a way that makes it difficult to supply the
`--no-binary` override for `pip`. Instead, we've downgraded to a version
prior to wheel support.

Lastly, the `libpq5` and `libpq-dev` dependencies needed to be
downgraded as well. This is because `psycopg2==2.6.2` is unable to make
sense of a `libpq` version greater than 9.

See: psycopg/psycopg2#543

deployment/ansible/roles.yml

@@ -17,7 +17,7 @@
   version: 0.1.0
 
 - src: azavea.postgresql-support
-  version: 0.3.0
+  version: 0.4.0
 
 - src: azavea.postgresql
   version: 0.3.0

deployment/ansible/roles/bee-pollinator.base/meta/main.yml

@@ -3,4 +3,6 @@ dependencies:
   - { role: "azavea.ntp" }
   - { role: "azavea.git" }
   - { role: "azavea.daemontools" }
-  - { role: "azavea.postgresql-support" }
+  - role: "azavea.postgresql-support"
+    postgresql_support_libpq_version: "9.3.*"
+    postgresql_support_psycopg2_version: "2.6.*"

deployment/ansible/roles/bee-pollinator.base/tasks/dependencies.yml

@@ -6,12 +6,7 @@
     - "libproj-dev=4.8.0*"
     - "gdal-bin=1.10.1*"
     - "libgdal1-dev=1.10.1*"
-  when: "['tile-servers'] | is_not_in(group_names)"
-
-- name: Configure the main PostgreSQL APT repository
-  apt_repository: repo="deb http://apt.postgresql.org/pub/repos/apt/ {{ ansible_distribution_release}}-pgdg main"
-                  state=present
 
 - name: Install PostgreSQL client
-  apt: pkg=postgresql-client-{{ postgresql_version }}={{ postgresql_package_version }}
+  apt: pkg=postgresql-client-9.3