docs(readme): add Greenkeeper badge

README.md

@@ -1,5 +1,7 @@
 # Lychee
 
+[![Greenkeeper badge](https://badges.greenkeeper.io/electerious/Lychee.svg)](https://greenkeeper.io/)
+
 #### A great looking and easy-to-use photo-management-system.
 
 *Since the 1st of April 2018 this project has moved to it's own Organisation (https://github.com/LycheeOrg) where people are able to submit their fixes to it. We, the Organisation owners, want to thank electerious (Tobias Reich) for the opportunity to make this project live on.*

greenkeeper.json

@@ -0,0 +1,9 @@
+{
+  "groups": {
+    "default": {
+      "packages": [
+        "src/package.json"
+      ]
+    }
+  }
+}

src/package.json

@@ -18,15 +18,15 @@
     "basiccontext": "^3.5.1",
     "basicmodal": "^3.3.8",
     "gulp": "^3.9.1",
-    "gulp-autoprefixer": "3.1.1",
-    "gulp-babel": "^6.1.2",
+    "gulp-autoprefixer": "5.0.0",
+    "gulp-babel": "^7.0.1",
     "gulp-concat": "^2.6.1",
     "gulp-inject": "^4.2.0",
     "gulp-load-plugins": "^1.5.0",
     "gulp-minify-css": "^1.2.4",
     "gulp-rimraf": "^0.2.1",
-    "gulp-sass": "^3.1.0",
-    "gulp-uglify": "^2.1.1",
+    "gulp-sass": "^4.0.1",
+    "gulp-uglify": "^3.0.0",
     "jquery": "^3.2.0",
     "jquery-ui": "^1.12.1",
     "mousetrap": "^1.6.0"