v0.0.20

pcvct v0.0.20

Diff since v0.0.19

Merged pull requests:

• export PhysiCellSnapshot and PhysiCellSequence (#110) (@drbergman)
• v0.0.20 (#111) (@drbergman)
• add support for computing connected components (#112) (@drbergman)
• use PairCorrelationFunction.jl to calc pcf (#113) (@drbergman)
• more informative printing in VCTLoader.jl (#114) (@drbergman)