Monte-carlo-contracts

* Discounting (`Model.discount`)
* Evaluation (`Model.evaluate`)
* String representations for contracts and observables

* Simulation of basic contract `Until`
* Currency conversion of `IndexedCashflows`
* `Or` contract supports multiple currencies
* `ObservableFloat` supports `<`, `<=`, `>` and `>=` operators with `float` or other `ObservableFloat` instances
* `ObservableBool` supports `~`, `&` and `|` operators for combined conditions
* [Equity Options](examples/Equity%20Options.ipynb) and [FX Options](examples/FX%20Options.ipynb) examples

* Simulation of basic contracts `Zero`, `One`, `Give`, `Scale`, `And`, `When` and `Cond`
* Partial simulation of `Or` contract
* Float observables `Stock` and `FX`
* Boolean observables `At`
* `SimulatedCashflows` and model-bound `IndexedCashflows` to represent cashflows
* Basic `Model` allowing the generation of cashflows for the contracts above

* Created using [cookiecutter-pyscript](https://github.com/luphord/cookiecutter-pyscript)