Eddy v0.3.1

Fixes bug where, when eddy is imported as a package, multiple runs of eddy.main() would result in appending the results from all previous runs being appended to each new output as the global_variables file is initialised on import rather than per run.

A patch has been applied to fix this issue, however, it is expected that a future update will remove all dependence on global variables an implement a class-based alternative where each eddy run creates an object with all the data currently stored in global variables as attributes of that object.