1345638 - Switch from npm-shrinkwrap to yarn

Status: RESOLVED FIXED

(Taskcluster :: Workers, enhancement)

Description

[Brian Stack [:bstack]]

Once this is on a modern version of node, we can switch to yarn. Steps we've been using so far for the other services:

0. npm test to establish a baseline
1. remove the ^ from node version in package.json engines (optionally make it the latest version of that version of node)
2. replace npm in package.json engines with yarn set to 0.21.3
3. add "engine-strict": true, to package.json right above engines
4. rm -r node_modules
5. git rm npm-shrinkwrap.json
6. yarn install
7. Update .taskcluster.yml and/or .travis.yml to make sure they don't still use npm install
7.4 In travis.yml, add yarn: true to the caches object
7.5. There is a bug in node-docker right now so if there is a .taskcluster.yml, you need to add  `yarn global add node-gyp` before `yarn install`
8. yarn test to see that it all still works
9. make changes to the Readme if needed
10. commit and make a PR!
11. move onto the next service/library