Squashed 'packages/mr/' changes from 3d616f2..fd29e2b

baacf8c 0.12.6
f6ccae6 Merge pull request #10 from Stuk/production
3198279 Update readme to mention devDependencies and production mode
40f2827 Add spec for production mode
64d7029 Add a description to package.json
7d513c0 Don't create mappings for devDependencies when in production mode

git-subtree-dir: packages/mr
git-subtree-split: fd29e2b1d57d8d35a6cc8e2043c4e79fde13af1d
Update Mr to v0.12.6
Merge pull request #1106 from Stuk/mr-0.12.6

Update Mr to v0.12.6