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/mailru/easyjson/jlexer/error.go

@@ -0,0 +1,15 @@
+package jlexer
+
+import "fmt"
+
+// LexerError implements the error interface and represents all possible errors that can be
+// generated during parsing the JSON data.
+type LexerError struct {
+	Reason string
+	Offset int
+	Data   string
+}
+
+func (l *LexerError) Error() string {
+	return fmt.Sprintf("parse error: %s near offset %d of '%s'", l.Reason, l.Offset, l.Data)
+}