This new minor version brings with it a number of new features and a few incompatibilities that should be tested for before switching PHP versions in production environments.
See also the migration guides for PHP versions 5.0.x, 5.1.x, 5.2.x, 5.3.x, 5.4.x, 5.5.x, 5.6.x, 7.0.x, 7.1.x and 7.2.x.