Not requiring perses for testing hybrid topology implementation

[ijpulidos]

In order to test our implementation of the HybridTopologyFactory we are relying on perses for the tests. See for example #24 . Please note that we are only requiring perses exclusively for testing purposes.

In the future we would like not to rely on perses, additionally not relying on OpenEye, to test our infrastructure. Many of the tests rely in intermediate objects (such as the TopologyProposal that I don't know if we are going to need to have our implementation of similar objects. This is something to discuss.