Unpin suds dependency version

Fixes bug #1133247

suds is used by the vmware driver and the dependency has always been
pinned to 0.4:

  67e63ba8 (Sateesh Chodapuneedi 2011-03-07 18:10:48 +0530 17) suds==0.4

0.4 was released in September 2010 and there hasn't been a release
since. In fact, there has only been 16 commits since then and none of
them look to break the existing API.

If there's no reason to expect the next version to break us, we should
unpin. Indeed, we want to know early if upstream does break its API.

Change-Id: Icd2bdd021093293b2e4261a00d063239a3c42ce6