Refactor all auth adapters to reduce duplications (#4954)

* Refactor all auth adapters to reduce duplications

* Adds mocking and proper testing for all auth adapters

* Proper testing of the google auth adapter

* noit

src/Adapters/Auth/httpsRequest.js

@@ -0,0 +1,41 @@
+const https = require('https');
+
+function makeCallback(resolve, reject, noJSON) {
+  return function(res) {
+    let data = '';
+    res.on('data', (chunk) => {
+      data += chunk;
+    });
+    res.on('end', () => {
+      if (noJSON) {
+        return resolve(data);
+      }
+      try {
+        data = JSON.parse(data);
+      } catch(e) {
+        return reject(e);
+      }
+      resolve(data);
+    });
+    res.on('error', reject);
+  };
+}
+
+function get(options, noJSON = false) {
+  return new Promise((resolve, reject) => {
+    https
+      .get(options, makeCallback(resolve, reject, noJSON))
+      .on('error', reject);
+  });
+}
+
+function request(options, postData) {
+  return new Promise((resolve, reject) => {
+    const req = https.request(options, makeCallback(resolve, reject));
+    req.on('error', reject);
+    req.write(postData);
+    req.end();
+  });
+}
+
+module.exports = { get, request };