Adding unit test for ToURL

Signed-off-by: Jonas Franz <info@jonasfranz.de>

plugin_test.go

@@ -0,0 +1,11 @@
+package main
+
+import "testing"
+
+func TestConfig_ToURL(t *testing.T) {
+	exampleConfig := &Config{Identifier: "test", Key: "MYKEY"}
+	result := exampleConfig.ToURL()
+	if result != "https://api.crowdin.com/api/project/test/update-file?key=MYKEY" {
+		t.Fatalf("ToURL returns \"%s\" instead of the expected \"%s\"", result, "https://api.crowdin.com/api/project/test/update-file?key=MYKEY")
+	}
+}