[minor] Update cipher ordering

Should match mozilla/server-side-tls#69

src/mig/client/client.go

@@ -67,12 +67,12 @@ func NewClient(conf Configuration, version string) (cli Client, err error) {
 		TLSClientConfig: &tls.Config{
 			MinVersion: tls.VersionTLS10,
 			CipherSuites: []uint16{
-				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
 				tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
 				tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
 				tls.TLS_RSA_WITH_AES_128_CBC_SHA,
 				tls.TLS_RSA_WITH_AES_256_CBC_SHA,
 			},