Ignore environment configurations

Gatsby makes active use of `.env.*` files. It's better to ignore the most common ones. Source: https://www.gatsbyjs.com/docs/environment-variables/#client-side-javascript

Author: fedetibaldo

.gitignore

@@ -58,6 +58,8 @@ typings/
 
 # dotenv environment variables file
 .env
+.env.development
+.env.production
 
 # IDE
 .idea/*
@@ -75,4 +77,4 @@ yarn-error.log
 .netlify/
 
 # Local Netlify folder
-.netlify
+.netlify