Add react dropzone library

Author: Mitchel Severe

package.json

@@ -103,6 +103,7 @@
     "react-d3-tree": "^1.12.3",
     "react-dom": "^16.4.1",
     "react-draggable": "^3.0.5",
+    "react-dropzone": "^10.2.1",
     "react-konva": "^16.12.0-0",
     "react-redux": "^5.0.7",
     "react-sortable-tree": "^2.2.0",