Error message formating

[blzaugg]

For this line: https://github.com/marcelklehr/nodist/blob/4f7164b115f8951c98074ba89208dbe0e9511c5f/src/shim-npm.go#L41

I got an error as:

Sorry, there's a problem with nodist. Couldn't resolve node version spec %s: %s nodev0.12.0 
Unexpected character in constraint nodev0.12.0: node

I would have expected something like this instead:

Sorry, there's a problem with nodist. Couldn't resolve node version spec nodev0.12.0: 
Unexpected character in constraint 

I assume the %s are not being replace as expected.

[blzaugg]

Side note, this error wasn't clear, that it was my version spec located in my .node-version file that was causing the issue.

What I had (from an old nodist version):

nodev0.12.0

What I should have had:

0.12.0