CHANGELOG for 3.1.x

This changelog references the relevant changes (bug and security fixes) done in 3.1 minor versions.

3.1.0 (2018-12-21)

270: Show the name of the database being purged when loading fixtures thanks to @alcaeus
265: Drop support for PHP < 7.1 and older versions of data-fixtures thanks to @alcaeus
260: Add fixture groups via a static method interface or service tags thanks to @weaverryan
269: Apply Doctrine Coding Standard thanks to @carusogabriel
219: Dynamic namespace thanks to @MassiveHiggsField