Clean tests

Author: Stephane Landelle

api/src/test/java/org/asynchttpclient/async/AbstractBasicTest.java

@@ -216,7 +216,7 @@ public void tearDownGlobal() throws Exception {
             server.stop();
     }
 
-    protected int findFreePort() throws IOException {
+    protected synchronized int findFreePort() throws IOException {
         ServerSocket socket = null;
 
         try {

api/src/test/java/org/asynchttpclient/async/BasicHttpsTest.java

@@ -200,9 +200,9 @@ public void reconnectsAfterFailedCertificationPath() throws Throwable {
                 Throwable cause = e.getCause();
                 if (cause instanceof ConnectException) {
                     assertNotNull(cause.getCause());
-                    assertTrue(cause.getCause() instanceof SSLHandshakeException);
+                    assertTrue(cause.getCause() instanceof SSLHandshakeException, "Expected an SSLHandshakeException, got a " + cause.getCause());
                 } else {
-                    assertTrue(cause instanceof SSLHandshakeException);
+                    assertTrue(cause.getCause() instanceof SSLHandshakeException, "Expected an SSLHandshakeException, got a " + cause);
                 }
             }