Add definition 5.4.18 - #141

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Chmod +x definition 5.4.18 - #141

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Update STABLE_DEFINITIONS with 5.4.18 - #141

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Update travis.yml to run 5.4.18 - #141

Fix #141: Need definition for 5.4.18 stable

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Merge pull request #143 from rogeriopradoj/fix-141

Fix #141: Need definition for 5.4.18 stable