Add autocert and nacl (#1698)

Autocert is a Go maintained project that facilitates provisioning TLS
certificates and starting a server using those certificates.

kevinburke/nacl implements all of the NaCL API's in Go, in a way
that's compatible with the C library offered here:
https://nacl.cr.yp.to.

README.md

@@ -986,11 +986,14 @@ See [go-hardware](https://github.com/rakyll/go-hardware) for a comprehensive lis
 *Libraries that are used to help make your application more secure.*
 
 * [acmetool](https://github.com/hlandau/acme) - ACME (Let's Encrypt) client tool with automatic renewal.
+* [autocert](https://godoc.org/golang.org/x/crypto/acme/autocert) - Auto
+  provision Let's Encrypt certificates and start a TLS server.
 * [BadActor](https://github.com/jaredfolkins/badactor) - In-memory, application-driven jailer built in the spirit of fail2ban.
 * [go-yara](https://github.com/hillu/go-yara) - Go Bindings for [YARA](https://github.com/plusvic/yara), the "pattern matching swiss knife for malware researchers (and everyone else)".
 * [goSecretBoxPassword](https://github.com/dwin/goSecretBoxPassword) - A probably paranoid package for securely hashing and encrypting passwords.
 * [lego](https://github.com/xenolf/lego) - Pure Go ACME client library and CLI tool (for use with Let's Encrypt).
 * [memguard](https://github.com/awnumar/memguard) - A pure Go library for handling sensitive values in memory.
+* [nacl](https://github.com/kevinburke/nacl) - Go implementation of the NaCL set of API's.
 * [passlib](https://github.com/hlandau/passlib) - Futureproof password hashing library.
 * [secure](https://github.com/unrolled/secure) - HTTP middleware for Go that facilitates some quick security wins.
 * [simple-scrypt](https://github.com/elithrar/simple-scrypt) - Scrypt package with a simple, obvious API and automatic cost calibration built-in.