New Provider: GANDI-LIVEDNS (API v5) (#320)

* Add gandi LiveDNS api provider
* vendor testify and gandi live DNS
* govendor update github.com/prasmussen/gandi-api/{client,live_dns}
* Fix Gandi-livedns TXT unit test
* TravisCI should use go 1.10

vendor/github.com/stretchr/objx/security.go

@@ -0,0 +1,14 @@
+package objx
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+)
+
+// HashWithKey hashes the specified string using the security
+// key.
+func HashWithKey(data, key string) string {
+	hash := sha1.New()
+	hash.Write([]byte(data + ":" + key))
+	return hex.EncodeToString(hash.Sum(nil))
+}