v0.9.9 - moved 'prop-types' to dependencies

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-animate-height",
-  "version": "0.9.8",
+  "version": "0.9.9",
   "description": "Lightweight, no dependency React component for animating height using CSS transitions.",
   "main": "lib/AnimateHeight.js",
   "author": "Stanko",
@@ -13,7 +13,8 @@
     "url": "https://github.com/Stanko/react-animate-height/issues"
   },
   "dependencies": {
-    "classnames": "^2.2.5"
+    "classnames": "^2.2.5",
+    "prop-types": "^15.5.8"
   },
   "devDependencies": {
     "babel-eslint": "^4.1.3",
@@ -24,8 +25,7 @@
     "react": "^15.5.4",
     "prop-types": "^15.5.8",
     "react-component-gulp-tasks": "^0.7.6",
-    "react-dom": "^15.5.4",
-    "prop-types": "^15.5.8"
+    "react-dom": "^15.5.4"
   },
   "peerDependencies": {
     "react": "15.x",