AUTH-1511: Add custom headers for ssh command

cmd/cloudflared/access/carrier_test.go

@@ -0,0 +1,18 @@
+package access
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBuildRequestHeaders(t *testing.T) {
+	headers := make(http.Header)
+	headers.Add("client", "value")
+	headers.Add("secret", "safe-value")
+
+	values := buildRequestHeaders([]string{"client: value", "secret: safe-value", "trash"})
+	assert.Equal(t, headers.Get("client"), values.Get("client"))
+	assert.Equal(t, headers.Get("secret"), values.Get("secret"))
+}