tweak the bower dependencies

work around a missing bower2nix features.

see https://github.com/rvl/bower2nix/issues/19

bower.json

@@ -45,7 +45,7 @@
     "localforage": "^1.5.2",
     "html2canvas": "^0.4.1",
     "croppie": "^2.5.0",
-    "sortablejs": "#^1.6.0",
+    "sortablejs": "^1.6.0",
     "saferphore": "^0.0.1",
     "jszip": "Stuk/jszip#^3.1.5",
     "requirejs-plugins": "^1.0.3"