Add a vars file for Ubuntu 18.04 Bionic

Since, just like Ubuntu 16.04, Ubuntu 18.04 has some divergent variables
that need to be set. The PostGIS plugin, for instance, isn't installable
without these variable values.

This commit adds a vars file for Ubuntu 18.04 with variables that are
specific to that family.

Signed-off-by: Jason Rogena <jason@rogena.me>

Author: jasonrogena

vars/bionic.yml

@@ -0,0 +1,10 @@
+---
+# PostgreSQL vars for Ubuntu Bionic (18.04LTS)
+
+postgresql_ext_postgis_deps:
+  - libgeos-c1v5
+  - "postgresql-{{postgresql_version}}-postgis-{{postgresql_ext_postgis_version}}"
+  - "postgresql-{{postgresql_version}}-postgis-scripts"
+
+postgresql_fdw_mysql_packages: "postgresql-{{ postgresql_version }}-mysql-fdw"
+postgresql_fdw_ogr_packages: "postgresql-{{ postgresql_version }}-ogr-fdw"