Version 2.1.7

What's Changed

• synapse models support heterogeneuos weights by @chaoming0625 in #170
• more efficient synapse implementation by @chaoming0625 in #171
• fix input models in brainpy.dyn by @chaoming0625 in #172
• fix: np array astype by @ztqakita in #173
• update README: 'brain-py' to 'brainpy' by @chaoming0625 in #174
• fix: fix the updating rules in the STP model by @c-xy17 in #176
• Updates and fixes by @chaoming0625 in #177

Full Changelog: V2.1.5...V2.1.7