Update changelog for next release

Author: jfritschi

docs/ChangeLog

@@ -1,3 +1,17 @@
+Changes in version 1.4.0
+
+Bug Fixes:
+   * Remove ineffective test annotations @outputBuffering [#379] (François Freitag)
+   * Fix travis-ci build process and remove PHP5 support [#366] (Joachim Fritschi)
+   * Fix use of deprecated setDebug() in examples [#360] (Joachim Fritschi)
+   * Fix session_set_save_handler error [#365] (Joachim Fritschi)
+   * Fix wrong server_port documentation [#369] (Joachim Fritschi)
+      
+Improvement:
+   * support samesite cookies attribute (#370) (Mickael)
+   * Remove PHP5 support [#366] (Joachim Fritschi)
+ 
+ 
 Changes in version 1.3.9
 
 Bug Fixes: