Changelog for package behaviortree_cpp

2.2.0 (2018-11-20)

fix typo
method contains() added to BlackBoard
back compatible API change to improve the wrapping of legacy code (issue #15) Eventually, SimpleAction, SimpleDecorators and SimpleCondition can use blackboard and NodeParameters too.
reduce potential memory allocations using string_view
fix important issue with SubtreeNode
Read at every tick the parameter if Blackboard is used
Adding NodeParameters to ParallelNode
travis update
merge pull request #14 related to #10 (with some minor changes)
Fix issue #8 and warning reported in #4 Fixed problem of visibility with TinyXML2
Contributors: Davide Faconti, Uilian Ries