Update commander to version 2.9.0 🚀

[greenkeeperio-bot]

Hello 👋

🚀🚀🚀

commander just published its new version 2.9.0, which is not covered by your current version range.

If this pull request passes your tests you can publish your software with the latest version of commander – otherwise use this branch to work on adaptions and fixes.

Happy fixing and merging 🌴

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GitHub Release

• Add option isDefault to set default subcommand #415 @Qix-
• Add callback to allow filtering or post-processing of help text #434 @djulien
• Fix undefined text in help information close #414 #416 @zhiyelee

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The new version differs by 22 commits .

• b2aad7a Merge pull request #453 from zhiyelee/master
• 39e5901 version bump
• 272e22f Merge pull request #450 from zhiyelee/lizhiye/fixtest
• 7689126 fix package for v0.6
• 8024df2 fix nohelp test
• 1559b3e Merge pull request #416 from zhiyelee/zhiyelee/fixHelpUndefined
• e553d4c add test
• 86467e3 Merge pull request #448 from zhiyelee/lizhiye/travis
• 2eeedaa update travis
• 0a14d4c merge master
• 4d421f9 add callback to allow filtering or post-processing of help text
• 0af40a5 Merge pull request #415 from Qix-/default-subcommand
• 0238972 Merge pull request #417 from zhiyelee/zhiyelee/refactor_test
• 93c5321 refactor test with sinion stub
• 619c648 fix the undefined in help #414

There are 22 commits in total. See the full diff.

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