Use connect and send in examples and remove some warnings

[spebern]

Hi,

Thanks for this library!

I had some trouble using it, by only looking at the examples because they use send without connecting.

I replaced it with connect_and_send in the examples (also suggested in #15).

I also removed two unused imports in the exmaples and handled one warning.

All the best, bold

[dignifiedquire]

thank you!