* uses lastest ece(1.7.2) and vapid libraries (1.2.1)
* Will attempt to autofill vapid `aud` from the endpoint if VAPID
requested
* Allows for the older `'aesgcm'` and newer, albeit not as widely
supported `'aes128gcm'` encryption content types.
* Includes fixes provided by https://github.com/Flimm
NOTE: Currently BLOCKED due to
https://github.com/martinthomson/encrypted-content-encoding/issues/36
closes: #49, #48, #42
use new "content_type" argument to specify either "aesgcm" (draft-01)
or "aes128gcm" (draft-04).
NOTE: Not all clients yet support Draft-04.
closes #33
Updated libraries and tests for latest depenedent library versions.
Note: can't tie in requires.io quite yet, investigating how to best do
that.
fixes: #18
* Added more information to README.
* Replaced curl call with requests per @safwanrahman
* cleaned up requirements, var names
* stripped vapid stuff (while still strongly urged, should be external)
* collected code beneath __init__
* 100% coverage
TODO: sphinx, travis, coverage