Lock jspdf version to avoid issue with 1.5.3

Author: eKoopmans

package.json

@@ -29,7 +29,7 @@
   "dependencies": {
     "es6-promise": "^4.2.5",
     "html2canvas": "^1.0.0-alpha.12",
-    "jspdf": "^1.4.1"
+    "jspdf": "1.4.1"
   },
   "devDependencies": {
     "babel-core": "^6.26.3",