Ditch enacl, support DH448 and Blake2s, and fix types (#14)

* Remove get_stacktrace (deprecated since OTP-24)

* Add DH448 support and switch to crypto:generate_key for DH25519

* Switch to crypto:hash/2 for Blake2b and support Blake2s

* Switch last enacl calls to crypto - no more enacl

* Eqwalizer fixes

Ewqalizer fix

Eqwalizer fix

Eqwalizer fix

Eqwalizer fix

Eqwalizer support

Eqwalizer fix

Fix tests to follow types (remote keys)

* More error handling on setup

* Dialyzer fix

* Write CHANGELOG

* Note about type-checking in README

src/enoise.app.src

@@ -5,7 +5,7 @@
   {applications,
    [kernel,
     stdlib,
-    enacl
+    crypto
    ]},
   {env,[]},
   {modules, []},