Endpoints JWT authentication BAD_FORMAT under Python3

[wsnel]

In which file did you encounter the issue?

https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/endpoints/getting-started/clients/google-jwt-client.py

Did you change the file? If so, how?

Added .decode('utf-8') in below snippet:

def make_request(host, api_key, signed_jwt):
.
.
.
headers = {
'Authorization': 'Bearer {}'.format(signed_jwt.decode('utf-8'))
}

Describe the issue

When running the example in python3, the string signed_jwt ends up being a 'binary' string. Without the .decode('utf-8'), the Authorization header will not be formatted correctly and will result in a 'BAD_FORMAT' error response.
Consider adding the following comment above the Authorization line:
* "# add .decode('utf-8') to signed_jwt when running under python3"

[daniel-sanche]

Thanks, I opened a PR to address this here: #2225

I should note the google_id_jwt function will still have Python3 issues as is, since httplib was renamed between versions. But this change adds full compatibility to make_request at least