v0.5.0

MatrixProductBP v0.5.0

Diff since v0.4.0

Merged pull requests:

• Improve documentation for RecursiveBPFactor methods (#121) (@stecrotti)
• Prefer using over import (#122) (@stecrotti)
• Added the heterogeneous SIS model (#123) (@FedericoFlorio)
• New version (#124) (@stecrotti)