avn does not handle release names

[Abraham]

Please describe your issue clearly and also include all details below.
It is possibly to have a .nvmrc point at (for example lts/boron) This is currently not supported by avn.
Details

_avn --version: 0.2.3
node --version: nvm is working (without avn) so this kinda depends
nvm --version: 0..33.2
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin16)
Copyright (C) 2007 Free Software Foundation, Inc.

My directory does not have a .node_version file, uses .nvmrc. But the output of __avn_debug is:

avn could not activate node lts/boron
error: no plugin passed predicate
  avn-nvm: no version matching lts/boron
  avn-n: no version matching lts/boron

avn is loaded in my ~/.bash_profile file with:

• [ x] As an nvm user I am confirming that I did not install with Homebrew

[Whitney Young]

Duplicate of #43.