fix(forex): reduce distribution size

For the browser, use XMLHttpRequest, instead of node https shim, to get JSON data.  Reduces the minified version by 80 KB.

browser/.jshintrc

@@ -0,0 +1,16 @@
+{
+    "esversion": 6,
+    "curly": true,
+    "eqeqeq": true,
+    "immed": true,
+    "latedef": true,
+    "newcap": true,
+    "noarg": true,
+    "sub": true,
+    "undef": true,
+    "unused": true,
+    "boss": true,
+    "eqnull": true,
+    "browser": true,
+    "predef": ['Money', 'XMLHttpRequest']
+}

browser/secure-json.js

@@ -0,0 +1,21 @@
+'use strict';
+
+function getSecureJSON(url) {
+    return new Promise((resolve, reject) => {
+        var xhr = new XMLHttpRequest();
+        xhr.open('GET', url);
+        xhr.onload = function () {
+            if (this.status < 200 || this.status > 299) {
+                reject(new Error('Failed to get data: ' + this.status));
+            } else {
+                resolve(JSON.parse(xhr.response));
+            }
+        };
+        xhr.onerror = function () {
+            reject(new Error(xhr.statusText));
+        };
+        xhr.send();
+    });
+}
+
+module.exports = getSecureJSON;

lib/secure-json.js

@@ -1,5 +1,7 @@
 // Thanks Tomas Dvorak for the initial idea (https://www.tomas-dvorak.cz/posts/nodejs-request-without-dependencies/)
 
+// NOTE: the dist copy (for the browser) uses '../browser/secure-json.js' not this file!!!
+
 'use strict';
 
 const https = require('https');

package.json

@@ -7,6 +7,7 @@
   "main": "index.js",
   "browser": {
       "index.js": "browser.js",
+      "./lib/secure-json.js": "./browser/secure-json.js",
       "intl": false
   },
   "browserify": {