add cypress file and folder

.gitignore

@@ -6,3 +6,8 @@ frontend_app_html-document/dist/html-document.app.js
 frontend_lib/dist/tracim_frontend_lib.js
 npm-debug.log
 package-lock.json
+
+#ignore file or folder about cypress tests
+functionnal_tests/package.json
+functionnal_tests/cypress.json
+functionnal_tests/node_modules/