v0.1.0, 31/01/2014 -- Initial release
v0.2.0, 31/01/2014 -- search method now accepts empty params and takes default filters and attributes when available
v0.3.0, 05/02/2014 -- added tests and fixed some bugs
v0.4.0, 27/02/2014 -- using requests' stream = True on GET method when retrieving response
v0.4.1, 24/11/2014 -- fixed "KeyError: 'displayName' when calling BiomartDataset.search"
v0.5.0, 25/11/2014 -- design change: not using params dict to initialize classes, using **kwargs instead