Fix v_tracker not tracking as expected (closes snowplow#848)

Author: Paul Boocock

gulpfile.babel.js/rollup.js

@@ -1,9 +1,11 @@
 import { nodeResolve } from '@rollup/plugin-node-resolve';
 import commonjs from '@rollup/plugin-commonjs';
 import { babel } from '@rollup/plugin-babel';
+import json from '@rollup/plugin-json';
 import banner from 'rollup-plugin-banner'
 
 export const basePlugins = [
+    json(),
     nodeResolve({
         browser: true,
         dedupe: [ 'lodash', 'uuid' ],

package-lock.json

@@ -23,6 +23,7 @@
     "@babel/register": "^7.11.5",
     "@rollup/plugin-babel": "^5.2.1",
     "@rollup/plugin-commonjs": "^15.0.0",
+    "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-node-resolve": "^9.0.0",
     "@types/babel__core": "^7.1.9",
     "@types/jest": "^26.0.13",

package.json

@@ -75,12 +75,13 @@ import forEach from 'lodash/forEach';
 import { addEventListener } from './lib/helpers';
 import { InQueueManager } from './in_queue';
 import { Tracker } from './tracker';
+import { version as jsVersion } from '../../package.json'
 
 export function Snowplow(asynchronousQueue, functionName) {
   var documentAlias = document,
     windowAlias = window,
     /* Tracker identifier with version */
-    version = 'js-' + '<%= pkg.version %>', // Update banner.js too
+    version = 'js-' + jsVersion,
     /* Contains four variables that are shared with tracker.js and must be passed by reference */
     mutSnowplowState = {
       /* List of request queues - one per Tracker instance */