Switch to kingpin flags (#639)

* Switch to kingpin flags

* Fix logrus vendoring

* Fix flags in main tests

* Fix vendoring versions

vendor/github.com/sirupsen/logrus/terminal_solaris.go

@@ -0,0 +1,21 @@
+// +build solaris,!appengine
+
+package logrus
+
+import (
+	"io"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+// IsTerminal returns true if the given file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	switch v := f.(type) {
+	case *os.File:
+		_, err := unix.IoctlGetTermios(int(v.Fd()), unix.TCGETA)
+		return err == nil
+	default:
+		return false
+	}
+}