Upgrade to Go1.6, use vendor

Also make sure we're using a more recent version of godep

vendor/github.com/jessevdk/go-flags/termsize.go

@@ -0,0 +1,28 @@
+// +build !windows,!plan9,!solaris
+
+package flags
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+type winsize struct {
+	row, col       uint16
+	xpixel, ypixel uint16
+}
+
+func getTerminalColumns() int {
+	ws := winsize{}
+
+	if tIOCGWINSZ != 0 {
+		syscall.Syscall(syscall.SYS_IOCTL,
+			uintptr(0),
+			uintptr(tIOCGWINSZ),
+			uintptr(unsafe.Pointer(&ws)))
+
+		return int(ws.col)
+	}
+
+	return 80
+}