v0.2.2

• Feature: Omit root graph name unless explicitly assigned via graphviz.name attribute.
  (#28 by @rhelms and @clue)

  $graph = new Graph();
  $graph->setAttribute('graphviz.name', 'g');

• Feature: Remove unneeded dependency on graphp/algorithms.
  (#39 by @clue)

• Feature / Fix: Use UTF-8 encoding (Unicode) by default and respect charset attribute.
  (#27 by @Ithilias and @clue)

• Fix: Fix representing directed loop edges as directed edge
  (#37 by @clue)

• Add examples and documentation for GraphViz attributes, labels and record shapes.
  (#26 by @clue)

• Update test suite to support PHPUnit 6 and PHPUnit 5 and support running on legacy PHP 5.3 through PHP 7.2 and HHVM.
  (#24 by @clue)