Revert "make use of library request.el"

This reverts commit a9457ae1ca6f29d7deaa148cd423c469d68a7ebc.

There are some more kinks to be worked out for proper
integration with request.el.

Fixes #25
Merge pull request #26 from mgalgs/revert-request.el

Revert "make use of library request.el"