Update package.json

Author: ffMathy

package.json

@@ -14,7 +14,7 @@
         "@types/node": "latest",
         "ava": "^0.25.0",
         "ts-node": "^7.0.0",
-        "typescript": "^3.0.0-rc"
+        "typescript": "^3.0.0"
     },
     "ava": {
         "files": [