Add example of a get request to a server.

src/commonTest/kotlin/client/CServiceTest.kt

+package client
+
+import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.*
+import io.ktor.client.*
+import io.ktor.client.request.*
+
+class CServiceTest : StringSpec({
+    
+    "connect to express server" {
+        val client = HttpClient()
+        val result = client.get<String>("http://127.0.0.1:50000/")
+        result.shouldBe("Hello world!!")
+    }
+})