Added groups store

stores/groups.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const Datastore = require('nedb-promise');
+
+const groups = new Datastore({
+	autoload: true,
+	filename: 'data/groups.db',
+});
+
+groups.ensureIndex({
+	fieldName: 'id',
+	unique: true,
+});
+
+const addGroup = group =>
+	groups.insert(group);
+
+const listGroups = () =>
+	groups.find({});
+
+const managesGroup = group =>
+	groups.findOne({ id: group.id });
+
+module.exports = {
+	addGroup,
+	listGroups,
+	managesGroup,
+};