Add unit tests AuthenticationProviderClientTest, UsersRolesClientTest

src/test/java/eu/europa/ec/simpl/tlsgateway/configurations/ssl/AuthenticationProviderClientTest.java

+package eu.europa.ec.simpl.tlsgateway.configurations.ssl;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import eu.europa.ec.simpl.tlsgateway.configurations.microservices.AuthenticationProviderProperties;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@ExtendWith(MockitoExtension.class)
+public class AuthenticationProviderClientTest {
+
+    @Mock
+    private AuthenticationProviderProperties authenticationProviderProperties;
+
+    private AuthenticationProviderClient authenticationProviderClient;
+
+    @BeforeEach
+    public void init() {
+        when(authenticationProviderProperties.url()).thenReturn("http://authenticationprovider.junit.local");
+        var keyPairAlgorithm = "EC";
+        authenticationProviderClient =
+                new AuthenticationProviderClient(authenticationProviderProperties, keyPairAlgorithm);
+    }
+
+    @Test
+    public void loadPemCertificatesTest() {
+        try (var webClient = mockStatic(WebClient.class, RETURNS_DEEP_STUBS)) {
+            assertDoesNotThrow(() -> authenticationProviderClient.loadPrivateKey());
+            verify(WebClient.builder()).baseUrl("http://authenticationprovider.junit.local/keypair");
+        }
+    }
+}

src/test/java/eu/europa/ec/simpl/tlsgateway/configurations/ssl/UsersRolesClientTest.java

+package eu.europa.ec.simpl.tlsgateway.configurations.ssl;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import eu.europa.ec.simpl.tlsgateway.configurations.microservices.UsersRolesProperties;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@ExtendWith(MockitoExtension.class)
+public class UsersRolesClientTest {
+
+    @Mock
+    private UsersRolesProperties usersRolesProperties;
+
+    private UsersRolesClient usersRolesClient;
+
+    @BeforeEach
+    public void init() {
+        when(usersRolesProperties.url()).thenReturn("http://usersroles.junit.local");
+        usersRolesClient = new UsersRolesClient(usersRolesProperties);
+    }
+
+    @Test
+    public void loadPemCertificatesTest() {
+        try (var webClient = mockStatic(WebClient.class, RETURNS_DEEP_STUBS)) {
+            assertDoesNotThrow(() -> usersRolesClient.loadPemCertificates());
+            verify(WebClient.builder()).baseUrl("http://usersroles.junit.local/credential/download");
+        }
+    }
+}