Release v0.2.1

What's Changed

• adding getter method, get_train_fit_history, to retrieve private trai… by @ruipimentelfigueiredo in #6
• Several fixes to the case y=None. by @Smantii in #7
• Added max_calls and custom_logger. by @Smantii in #10
• Added sympy option. by @Smantii in #11
• Sympy getter by @Smantii in #13
• Generating unique individuals in the initial population. by @alucantonio in #8

Full Changelog: 0.2.0...0.2.1