Making Echo as simple as it was in v1

• Drop fasthttp support to keep the project simple, easy to maintain, aligned with standard library and compatible with community packages. As simple as it was in v1.
• Skipper function to conditionally skip a middleware
• Update docs
• Update recipes
  • Put back WebSocket
  • Put back Graceful shutdown
• Release notes and migrating guide
• Use standard lib for serving files Resumeable Static Content #471
• Wrap standard handler
• Wrap standard middleware
• Auto TLS via https://letsencrypt.org
• Map type as shorthand for map[string]interface{}
• Built-in graceful shutdown
• Embedding golang context can cause stack overflows #669 (comment)
• Remove static middleware
• and more...

@ericmdantas @o1egl @CaptainCodeman @mtojek @Anon-Penguin @gavv @01walid @ipfans @matcornic

Open for discussion