Upgrade to Go1.6, use vendor

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

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

@@ -0,0 +1,21 @@
+package flags
+
+import (
+	"reflect"
+)
+
+// Arg represents a positional argument on the command line.
+type Arg struct {
+	// The name of the positional argument (used in the help)
+	Name string
+
+	// A description of the positional argument (used in the help)
+	Description string
+
+	value reflect.Value
+	tag   multiTag
+}
+
+func (a *Arg) isRemaining() bool {
+	return a.value.Type().Kind() == reflect.Slice
+}