Adding trivial tests

src/test/java/at/ac/uibk/gitsearch/web/rest/errors/TrivialExceptionTest.java

+package at.ac.uibk.gitsearch.web.rest.errors;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.Test;
+
+public class TrivialExceptionTest {
+
+    @Test
+    public void testInvalidPasswordException() {
+    	InvalidPasswordException ex = new InvalidPasswordException();
+    	Assert.assertEquals("Incorrect password", ex.getMessage());
+    }
+
+    @Test
+    public void testBadRequestAlertException() {
+    	BadRequestAlertException ex = new BadRequestAlertException("defaultMessage", "entityName", "errorKey");
+    	Assert.assertEquals("entityName", ex.getEntityName());
+    }
+}