Update to 2.10.0
    
    Features
      * New hub pr --format fields %pS and %pC for PR state and color
        %pS: "open", "draft", "merged", or "closed"
        %pC: green, gray, purple, or red
      * Have commands with rich output respect the --color flag
        default: --color=auto
        --color is equivalent to --color=always
        --color=never disables color for TTYs
    Fixes
      * Make man pages parseable with whatis
      * Make hub checkout work independently of remote refspec