Support aiohttp 2.3.1 +

[hellysmile]

aiohttp 2.3 introduced explicit support for ssl.*Error

As well in upcoming 2.3.2 (bugfix release) will be private api changes for Connectors aio-libs/aiohttp#2446

It guess aiosocks integration will be broken

@nibrag What about to move aiosocks connector to aiohttp itself?

[nibrag]

Fixed #21

@hellysmile

What about to move aiosocks connector to aiohttp itself?

aiosocks use python 3.5, aiohttp 3.4.2

[hellysmile]

master aiohttp uses python 3.5.3+

[nibrag]

@hellysmile
In progress
aio-libs/aiohttp#2539

[hellysmile]

@nibrag cool!