Setup Postgres for CI

.travis.yml

@@ -2,9 +2,16 @@ dist: trusty
 sudo: required
 services:
   - docker
+  - postgresql
 language: go
 go:
 - "1.11.5"
+addons:
+  postgresql: "10"
+  apt:
+    packages:
+    - postgresql-10
+    - postgresql-client-10
 
 # add TF_CONSUL_TEST=1 to run consul tests
 # they were causing timouts in travis
@@ -12,6 +19,7 @@ go:
 # if added, TF_ETCDV3_ENDPOINTS must be set to a comma-separated list of (insecure) etcd endpoints against which to test
 env:
   - CONSUL_VERSION=0.7.5 GOMAXPROCS=4 GO111MODULE=on
+  - DATABASE_URL=postgres://localhost/terraform_backend_pg_test?sslmode=disable
 
 # Fetch consul for the backend and provider tests
 before_install:
@@ -31,6 +39,7 @@ install:
 
 before_script:
 - git config --global url.https://github.com/.insteadOf ssh://git@github.com/
+- psql -c 'create database terraform_backend_pg_test;' -U postgres
 
 script:
 - make test