Merge pull request #4395 from jaswilli/pg

Add pg as an optional dependency.

.travis.yml

@@ -12,9 +12,6 @@ env:
   - DB=sqlite3 NODE_ENV=testing
   - DB=mysql NODE_ENV=testing-mysql
   - DB=pg NODE_ENV=testing-pg
-matrix:
-  allow_failures:
-    - env: DB=pg NODE_ENV=testing-pg
 before_install:
   - git clone git://github.com/n1k0/casperjs.git ~/casperjs
   - cd ~/casperjs
@@ -22,7 +19,7 @@ before_install:
   - export PATH=$PATH:`pwd`/bin
   - cd -
   - if [ $DB == "mysql" ]; then mysql -e 'create database ghost_testing'; fi
-  - if [ $DB == "pg" ]; then npm install pg; psql -c 'create database ghost_testing;' -U postgres; fi
+  - if [ $DB == "pg" ]; then psql -c 'create database ghost_testing;' -U postgres; fi
 before_script:
   - phantomjs --version
   - casperjs --version

package.json

@@ -65,7 +65,8 @@
         "xml": "0.0.12"
     },
     "optionalDependencies": {
-        "mysql": "2.5.2"
+        "mysql": "2.5.2",
+        "pg": "3.6.2"
     },
     "devDependencies": {
         "blanket": "~1.1.6",