fix(package): update @openui5/sap.ui.core to version 1.78.1

Closes #110

Author: greenkeeper[bot]

package.json

@@ -139,7 +139,7 @@
   },
   "dependencies": {
     "@openui5/sap.m": "1.77.2",
-    "@openui5/sap.ui.core": "1.77.2",
+    "@openui5/sap.ui.core": "1.78.1",
     "@openui5/themelib_sap_belize": "1.77.2",
     "c3": "https://github.com/pulseshift/c3#master",
     "d3": "5.16.0",