Ensure Content-Length is a string.
Fix #1106
Remove test that cannot work on Python3.
Fix failing tests.
missing algorithm field
Merge pull request #1117 from sigmavirus24/issue1106

Fix #1106
Merge pull request #1116 from Lukasa/master

Correct type of Content-Length headers.
Merge pull request #1125 from juanriaza/master

HTTPDigestAuth: missing algorithm field