Re-instated proxy test otherwise this breaks the code if no proxy is …

…set.

Set 0.5.0 release

Make sure to exclude build dir

Merge pull request #11 from cedadev/devel

Fix to ndg.httpsclient.utils.open_url utility function

Merge pull request #9 from cedadev/devel

0.4.1 release

Merge pull request #2 from cedadev/py3-devel

Py3 devel

Preparing 0.3.3 release.