setup.py: version bump to 0.3.3

Bump version to 0.3.3 in setup.py and sphinx.

setup.py: bump version to 3.0.1

Also update sphinx documentation.

setup.py: version bump to 0.3.0

Bump version to 0.3.0 as there are backward incompatible
changes in this release.

pytest-httpserver: version bump to 0.2.2

The reason for this release is the header value matcher which have been
added recently.

pytest-httpserver: version bump to 0.2.1

No actual code changes, only re-adding requirements-doc.txt to make RTD
happy.

pytest-httpserver: version bump to 0.2

See release notes for details.

releasenotes: add note about minor fixes

doc: make the documentation more complete