Allow rbx-2 tests to fail on Travis.

Gems seem to be problematic at the moment.
Use an SVG badge for CodeClimate in the README.
Update the supported ruby versions in the README.
Bump version number.
Update the changelog.
Refactor the XML input message fragment generator.

Now takes a port, rather than the value/filename directly.
Add list delimiter functionality to InputPort.

So we can upload lists of depth 1 without resorting to baclava.
Update the XML message fragment with a list delimiter.
Use a list delimiter instead of bacalva for depth 1 input ports.