Add fast-memoize library #5

Author: catalinmiron

package-lock.json

@@ -14,6 +14,7 @@
   "homepage": "https://github.com/catalinmiron/react-native-css-gradient#readme",
   "main": "index.js",
   "dependencies": {
+    "fast-memoize": "^2.5.1",
     "gradient-parser": "0.1.5"
   },
   "peerDependencies": {