Added call to donate after npm install

package.json

@@ -28,6 +28,7 @@
     "estraverse": "4.2.0",
     "inversify": "4.1.0",
     "mkdirp": "0.5.1",
+    "opencollective": "^1.0.3",
     "reflect-metadata": "0.1.10",
     "source-map-support": "0.4.15",
     "string-template": "1.0.0",
@@ -84,7 +85,8 @@
     "test:removeTmpDir": "scripts/test-remove-tmp-dir",
     "test": "scripts/test",
     "tslint": "scripts/tslint",
-    "travis": "scripts/travis"
+    "travis": "scripts/travis",
+    "postinstall": "opencollective postinstall"
   },
   "pre-commit": [
     "build"
@@ -92,5 +94,10 @@
   "author": {
     "name": "Timofey Kachalov"
   },
-  "license": "BSD-2-Clause"
-}
+  "license": "BSD-2-Clause",
+  "collective": {
+    "type": "opencollective",
+    "url": "https://opencollective.com/javascript-obfuscator",
+    "logo": "https://opencollective.com/opencollective/logo.txt"
+  }
+}