0.1.1

Add test

• Add more thorough test cases.

Code Improvement

• Update the optimal hyperparameter set for SphereNet in threedgraph. [#39](thanks to @kexinhuang12345 and @chao1224)
• Fix the Fidelity sign (to Fidelity-) for the fidelity_inv description in xgraph. [#43](thanks to @joaquincabezas)

Documentation Improvement

• Update the contribution instruction by adding more detailed descriptions.