Remove unused dev package.

thefrosty · thefrosty · commit 878ad307a758 · 2019-04-17T15:10:47.000-07:00
diff --git a/composer.json b/composer.json
@@ -18,7 +18,6 @@
     "php": ">=7.0.4"
   },
   "require-dev": {
-    "10up/wp_mock": "dev-dev",
     "phpunit/phpunit": "6.*",
     "squizlabs/php_codesniffer": "^3.2"
   },
