protocol - 0eff254

@0x/asset-swapper@5.5.0

• Bancor now supported in all pairs (#88)

@0x/contracts-asset-proxy@3.7.0

• Fix Bancor support of ETH (#88)

@0x/contracts-zero-ex@0.13.0

• Address audit feedback in UniswapFeature (#82)
• Always transfer msg.value to the liquidity provider contract in LiquidityProviderFeature to (#82)
• Remove backwards compatibility with old PLP/bridge interface in LiquidityProviderFeature and MixinZeroExBridge (#85)