Add # host for development and test as well

config/database.yml.mysql

@@ -25,6 +25,7 @@ development:
   pool: 5
   username: root
   password: "secure password"
+  # host: localhost
   # socket: /tmp/mysql.sock
 
 # Warning: The database defined as "test" will be erased and
@@ -39,4 +40,5 @@ test: &test
   pool: 5
   username: root
   password:
+  # host: localhost
   # socket: /tmp/mysql.sock