Move testing to 3001 port (#8)

Create separate database for testing
Add runtime configuration file support

config/development.json

@@ -0,0 +1,4 @@
+{
+  "port": 3000,
+  "database": ".db"
+}

config/index.js

@@ -0,0 +1,22 @@
+/**
+ * This module reads configuration file depending on NODE_ENV
+ *
+ * @type {module}
+ */
+
+const fs = require('fs');
+const path = require('path');
+const NODE_ENV = process.env.NODE_ENV || 'development';
+const configPath = `./${NODE_ENV}.json`;
+let config;
+
+if (fs.existsSync(path.resolve(__dirname, configPath))) {
+  config = require(configPath);
+} else {
+  config = {
+    database: '.db',
+    port: 3000
+  };
+}
+
+module.exports = config;

config/production.json

@@ -0,0 +1,4 @@
+{
+  "port": 3000,
+  "database": ".db"
+}

config/testing.json

@@ -0,0 +1,5 @@
+{
+  "port": 3001,
+  "database": ".testdb",
+  "rcFile": "./test/.codexdocsrc"
+}