fix(package): update d3 to version 5.4.0

Closes #10

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
         "cordova-plugin-ionic-webview": "^1.1.16",
         "cordova-plugin-splashscreen": "^5.0.1",
         "cordova-plugin-whitelist": "^1.3.3",
-        "d3": "^4.12.2",
+        "d3": "^5.4.0",
         "d3-array": "^1.2.1",
         "d3-axis": "^1.0.8",
         "d3-scale": "^2.0.0",