Merge pull request #62 from marcauberer/master

Fix typo in comment

isatty_windows.go

@@ -76,7 +76,7 @@ func isCygwinPipeName(name string) bool {
 }
 
 // getFileNameByHandle use the undocomented ntdll NtQueryObject to get file full name from file handler
-// since GetFileInformationByHandleEx is not avilable under windows Vista and still some old fashion
+// since GetFileInformationByHandleEx is not available under windows Vista and still some old fashion
 // guys are using Windows XP, this is a workaround for those guys, it will also work on system from
 // Windows vista to 10
 // see https://stackoverflow.com/a/18792477 for details