Simplify and split config.json into defaultPreferences and buildConfig

src/common/config/upgradePreferences.js

@@ -0,0 +1,29 @@
+const pastDefaultPreferences = require('./pastDefaultPreferences');
+
+function deepCopy(object) {
+  return JSON.parse(JSON.stringify(object));
+}
+
+function upgradeV0toV1(configV0) {
+  const config = deepCopy(pastDefaultPreferences['1']);
+  if (config.version !== 1) {
+    throw new Error('pastDefaultPreferences[\'1\'].version is not equal to 1');
+  }
+  config.teams.push({
+    name: 'Primary team',
+    url: configV0.url
+  });
+  return config;
+}
+
+function upgradeToLatest(config) {
+  var configVersion = config.version ? config.version : 0;
+  switch (configVersion) {
+  case 0:
+    return upgradeToLatest(upgradeV0toV1(config));
+  default:
+    return config;
+  }
+}
+
+module.exports = upgradeToLatest;