Minor bugfixes and improvements.

What's Changed

• Update constants.py [BSC support] by @liquid-8 in #129
• feat: added swapExact...SupportingFeeOnTransferTokens() support by @liquid-8 in #132
• fix/enhancement: removes over-approval, adds manual approve by @liquid-8 in #136
• Update getting-started.rst by @liquid-8 in #137
• fix: add '3' as valid Uniswap version number in error message by @nimcon in #157
• feat: Polygon support by @ChristianPerez34 in #158
• docs: update quoter description by @ekzhang in #153
• Fix v3 behaviour when input or output token is ETH by @nimcon in #159
• fix: added kovan to _netid_to_name by @jhb10c in #168
• build(deps): upgrade click by @unparalleled-js in #179
• fix: replace print with click.echo by @unparalleled-js in #180

New Contributors

• @nimcon made their first contribution in #157
• @ChristianPerez34 made their first contribution in #158
• @ekzhang made their first contribution in #153
• @jhb10c made their first contribution in #168
• @unparalleled-js made their first contribution in #179

Full Changelog: 0.5.1...0.5.3