Provider namespaces

[ferd]

The following now works:

λ rebar3 → provider-namespaces* → ./rebar3 new
app (built-in): OTP Application
lib (built-in): OTP Library application (no processes)
plugin (built-in): Rebar3 plugin
release (built-in): OTP Release structure for executable programs

λ rebar3 → provider-namespaces* → ./rebar3 lfe new
===> Command do not found in namespace lfe

λ rebar3 → provider-namespaces* → ./rebar3 default new
app (built-in): OTP Application
lib (built-in): OTP Library application (no processes)
plugin (built-in): Rebar3 plugin
release (built-in): OTP Release structure for executable programs

λ rebar3 → provider-namespaces* → ./rebar3 default new, new
app (built-in): OTP Application
lib (built-in): OTP Library application (no processes)
plugin (built-in): Rebar3 plugin
release (built-in): OTP Release structure for executable programs
app (built-in): OTP Application
lib (built-in): OTP Library application (no processes)
plugin (built-in): Rebar3 plugin
release (built-in): OTP Release structure for executable programs

λ rebar3 → provider-namespaces* → ./rebar3 lfe new, new
===> Command do not found in namespace lfe

λ rebar3 → provider-namespaces* → ./rebar3 do new
app (built-in): OTP Application
lib (built-in): OTP Library application (no processes)
plugin (built-in): Rebar3 plugin
release (built-in): OTP Release structure for executable programs

Would need a merge and version up on the providers repo.

Attempt to address #69

[ferd]

Trying to figure out failing tests

[ferd]

If we agree with this form of implementation, I'll go and try to add tests for error output and correct functioning -- I've just done hand-tests before.

[tsloughter]

I think it looks good. Want to merge it in and I'll modify erlydtl provider to work with it?

[ferd]

I'll try to add a few tests in before merging it. Hopefully won't be too long.