Merge pull request wp-cli#103 from wp-cli/update/wp-cli-2-12

Require `wp-cli/wp-cli` v2.12

Author: mrsdizzie

composer.json

@@ -12,7 +12,7 @@
         }
     ],
     "require": {
-        "wp-cli/wp-cli": "^2.5"
+        "wp-cli/wp-cli": "^2.12"
     },
     "require-dev": {
         "wp-cli/entity-command": "^1.3 || ^2",