Set custom timeout for requests #71

It would be nice to allow users to set custom timeout for requests.

In our test environment, we have problems because our servers are not reliable and this can lead to Timeout errors.

Retry of failed requests by Timeout error might fix the problem, but we do not need to retry if we increase the timeout, or maybe the server is under some load and all requests will be slower.

The idea is to create a way to set a custom timeout. If we follow the proposed way for retries of failed requests it should be an env variable.