Move grpc-php back to require-dev

Author: splittingred

composer.json

@@ -7,12 +7,12 @@
     { "type": "vcs", "url": "https://github.com/bigcommerce/grpc-php" }
   ],
   "require": {
-    "phpunit/php-timer": "1.0.*",
-    "bigcommerce/grpc-php": "1.3.2-p1"
+    "phpunit/php-timer": "1.0.*"
   },
   "require-dev": {
     "phpunit/phpunit": "6.1.*",
-    "phpunit/php-code-coverage": "^5.2@dev"
+    "phpunit/php-code-coverage": "^5.2@dev",
+    "bigcommerce/grpc-php": "1.3.2-p1"
   },
   "autoload": {
     "psr-4": { "": "src/"}