Bump github.com/mattn/go-isatty from 0.0.12 to 0.0.13

Bumps [github.com/mattn/go-isatty](https://github.com/mattn/go-isatty) from 0.0.12 to 0.0.13.
- [Release notes](https://github.com/mattn/go-isatty/releases)
- [Commits](mattn/go-isatty@v0.0.12...v0.0.13)

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -4,5 +4,5 @@ go 1.13
 
 require (
 	github.com/mattn/go-colorable v0.1.8
-	github.com/mattn/go-isatty v0.0.12
+	github.com/mattn/go-isatty v0.0.13
 )

go.sum

@@ -1,7 +1,8 @@
 github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
 github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
-github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/mattn/go-isatty v0.0.13 h1:qdl+GuBjcsKKDco5BsxPJlId98mSWNKqYA+Co0SC1yA=
+github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae h1:/WDfKMnPU+m5M4xB+6x4kaepxRw6jWvR5iDRdvjHgy8=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=