You can delete them
The files do serve a purpose but they are not used by the application at run time.
What are they for
- .editorconfig is a file used to help ensure code is consistently formatted.
- .travis.yml is a file used to configure automated builds using travis - so that the test suite runs automatically for commits and pull requests.
- build.xml is used to create a new release, and update pear using phing.
- build.properties is a configuration file containing info used by phing (see above) to parameters pirum - to update the cakephp pear channel.