Check in the vendor directory

Travis seems to be having issues pulling deps, so we'll have to check in
the vendor directory and prevent the makefile from trying to regenerate
it normally.

vendor/github.com/modern-go/concurrent/log.go

@@ -0,0 +1,13 @@
+package concurrent
+
+import (
+	"os"
+	"log"
+	"io/ioutil"
+)
+
+// ErrorLogger is used to print out error, can be set to writer other than stderr
+var ErrorLogger = log.New(os.Stderr, "", 0)
+
+// InfoLogger is used to print informational message, default to off
+var InfoLogger = log.New(ioutil.Discard, "", 0)