Rename an oil and gas industry sector tag

Rename the tag "oil-and-gas/exploration-and-development" to 
"oil-and-gas/exploration-and-production".

Nothing is currently tagged with this ID in any environment, so we don't 
need to migrate any artefacts over.
Merge pull request #114 from alphagov/rename-oil-and-gas-tag

Rename an oil and gas industry sector tag