renaming testing class (fix for #68)

src/test/java/org/etsi/osl/services/api/metrics/GeneralMetricsApiControllerTest.java

@@ -41,7 +41,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 //@TestPropertySource(
 //		  locations = "classpath:application-testing.yml")
 
-public class MetricsApiControllerTest {
+public class GeneralMetricsApiControllerTest {
 
     @Autowired
     private MockMvc mvc;