bug: yarn tag list prompted user for credentials removed

[seansabour]

Summary
This is a bug fix for issue #5325 that caused yarn tag list to prompt user for credentials. Running npm dist-tag ls will not prompt for credentials.

Test plan
I have not tested the code yet due to an issue with babel-eslint:

yarn run lint
yarn run v1.4.1
$ eslint . && flow check
Cannot read property 'type' of undefined
TypeError: Cannot read property 'type' of undefined
    at isForInRef (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/rules/no-unused-vars.js:406:24)
    at variable.references.some.ref (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/rules/no-unused-vars.js:443:21)
    at Array.some (<anonymous>)
    at isUsedVariable (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/rules/no-unused-vars.js:442:40)
    at collectUnusedVariables (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/rules/no-unused-vars.js:565:26)
    at Program:exit (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/rules/no-unused-vars.js:617:36)
    at listeners.(anonymous function).forEach.listener (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/safe-emitter.js:47:58)
    at Array.forEach (<anonymous>)
    at Object.emit (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/safe-emitter.js:47:38)
    at NodeEventGenerator.applySelector (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/node-event-generator.js:251:26)
    at NodeEventGenerator.applySelectors (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/node-event-generator.js:280:22)
    at NodeEventGenerator.leaveNode (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/node-event-generator.js:303:14)
    at CodePathAnalyzer.leaveNode (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/code-path-analysis/code-path-analyzer.js:630:23)
    at Traverser.leave [as _leave] (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/linter.js:1020:32)
    at Traverser._traverse (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/traverser.js:155:18)
    at Traverser.traverse (/Users/ssabour/Desktop/development/yarn/node_modules/eslint/lib/util/traverser.js:115:14)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Some searching brought me to this issue eslint/eslint#9767

P.S my first contribution to open source, so sorry for any misunderstanding

[arcanis]

Thanks!