Update "yargs" to version 3.32.0

[marekventur]

#3.32.0 / 2016-01-15

• custom parsing function support. raw argument strings can now be parsed. various other bug fixes
• Merge pull request #348 from bcoe/update-changelog
  update changelog for v3.32.0
• update changelog
• add changelog update
• Merge pull request #344 from bcoe/contributing
  added contributor code of conduct, and contribution guidelines
• made some edits based on @lrlna's code review
• Merge pull request #346 from bcoe/fix-341
  alias should be applied to camel-case form of argument
• alias should be applied to camel-case form of argument
• typo in email
• add contributing.md
• Merge pull request #339 from bcoe/cleanup-tests
  split(' ') is no longer needed in tests
• Merge pull request #340 from bcoe/reset-groups
  Clear groups in reset method
• clear groups in reset and enforce option uniqueness per group
• add tests for group reset and option uniqueness per group
• split(' ') is no longer needed in tests
• Merge pull request #331 from bcoe/parse-string
  allow yargs.parse() and yargs(foo).argv to accept a raw argument string
• update readme/changelog
• parse() and yargs().argv can now parse a raw argument string
• yargs can now directly parse an argument string
• changelog update
• Merge pull request #326 from bcoe/upgrade-nyc
  update of #325 (Make tests pass on Windows)
• upgrade to newest version of nyc
• test: Windows files have \r chars in them
• Specify test script as simply 'mocha', not _mocha
  For discussion, see: Upgrade foreground-child, remove unnecessary arg munging istanbuljs/nyc#123 (comment)
• Merge pull request #321 from bcoe/config-parsing-closure
  allow a custom parser to be passed to config()
• address @nexdrew's code review
• return the error object, based on @nexdrew's code review
• fix typo
• updates based on @nexdrew's code review
• allow a custom parser to be passed to config()
• Merge pull request #320 from maxrimue/fixed-engine-version
  Changed "engine" in package.json
• Changed "engine" in package.json
• Merge pull request #316 from josephfrazier/fix-typo-sigletonify
  Rename sigletonify to singletonify
• Rename sigletonify to singletonify