fix(uninstall): remove instance from global config on ghost uninstall

closes #205
- remove all instances with the same cwd as the installation on `ghost uninstall`

Author: acburdine

lib/commands/uninstall.js

@@ -1,5 +1,6 @@
 'use strict';
 const fs = require('fs-extra');
+const filter = require('lodash/filter');
 
 const stop = require('./stop');
 const Config = require('../utils/config');
@@ -37,6 +38,12 @@ module.exports.execute = function execute() {
 
         return this.ui.run(this.service.callHook('uninstall'), 'Removing related configuration');
     }).then(() => this.ui.run(() => {
+        let systemConfig = Config.load('system');
+        let cleanedInstances = filter(systemConfig.get('instances'), (instance) => {
+            return instance.cwd !== process.cwd();
+        });
+        systemConfig.set('instances', cleanedInstances).save();
+
         return Promise.all(fs.readdirSync('.').map(file => fs.remove(file)));
     }, 'Removing Ghost installation'));
 }