stack upload requires a build plan

[meteficha]

On a package without a stack.yaml, on a machine without GHC 7.8, stack upload doesn't work:

$ stack upload
Using resolver: lts-2.15 from global config file: /home/felipe/.stack/global/stack.yaml
Caching build plan
Populated index cache.    
GHC version mismatched, found 7.10.1 (x86_64), but expected version 7.8.4 (x86_64) (based on resolver setting in /home/felipe/.stack/global/stack.yaml). Try running stack setup

The older stackage upload won't complain:

$ stackage upload
Warning: Cannot run preprocessors. Run 'configure' command first.
Building source dist for fb-persistent-0.3.5...
Source tarball created:
/tmp/stackage-upload-tarball13706/fb-persistent-0.3.5.tar.gz
Uploading /tmp/stackage-upload-tarball13706/fb-persistent-0.3.5.tar.gz... done!

I'm not sure of the implications of not having a valid build plan before uploading.

[DanBurton]

Sounds like a regression to me.

[snoyberg]

Fixed for now I believe, though we'll have to think harder about the right way to solve this once #313 becomes a reality. @meteficha confirmed?

[meteficha]

I'm take your word for it after reading the commit and seeing it makes sense. Thanks!