Add a mechanism to configure environment variables.

src/config.ts

@@ -0,0 +1,34 @@
+// Look in ./config folder for config
+
+const path = require('path');
+
+let configContext = require.context("../config", false, /json$/);
+let EnvConfig : any = {};
+let EnvConfigFile : string;
+let CommonConfig : any = {};
+
+try {
+    CommonConfig = configContext('./environment.common.json');
+} catch (e) {
+    throw new Error(`Cannot find file "${path.resolve('config', './environment.common.json')}"`);
+}
+
+switch (process.env.NODE_ENV) {
+    case 'prod':
+    case 'production':
+        EnvConfigFile = './environment.prod.json';
+        break;
+    case 'dev':
+    case 'development':
+    default:
+        EnvConfigFile = './environment.dev.json';
+}
+try {
+    EnvConfig = configContext(EnvConfigFile);
+} catch (e) {
+    throw new Error(`Cannot find file "${path.resolve('config', EnvConfigFile)}"`);
+}
+
+const GlobalConfig = Object.assign(CommonConfig, EnvConfig);
+
+export {GlobalConfig}