Add gitflow hook

By adding the post-flow-release-start hook, the version is automatically added to the file.
Merge branch 'develop' of https://github.com/dongli/packman into develop

Conflicts:
	.hooks/post-flow-release-start
Update version information
Merge branch 'release/1.0.0-a5'
Merge tag '1.0.0-a5' into develop

Add gitflow hook