python-robotframework: bump 2.8.1 -> 2.8.4

Source URL is changing from googlecode to pypi; new releases are no
longer available on googlecode.
python-robotframework-ride: bump 1.2.2 -> 1.2.3

Remove the now unneeded postPatch phase; the fix has been integrated
into the upstream release.
python-robotframework-selenium2library: bump 1.4.0 -> 1.5.0