gen/template.py: add error message for unhandled switch/case value
gen/template.py: add error message for unhandled switch/case value

lingmann/dcos,vishnu2kmohan/dcos,BenWhitehead/dcos,kensipe/dcos,surdy/dcos,xinxian0458/dcos,BenWhitehead/dcos,GoelDeepak/dcos,dcos/dcos,mesosphere-mergebot/dcos,vishnu2kmohan/dcos,darkonie/dcos,GoelDeepak/dcos,xinxian0458/dcos,branden/dcos,lingmann/dcos,darkonie/dcos,xinxian0458/dcos,branden/dcos,darkonie/dcos,surdy/dcos,jeid64/dcos,mnaboka/dcos,dcos/dcos,surdy/dcos,asridharan/dcos,mnaboka/dcos,jeid64/dcos,mesosphere-mergebot/mergebot-test-dcos,mesosphere-mergebot/mergebot-test-dcos,GoelDeepak/dcos,dcos/dcos,jeid64/dcos,mesosphere-mergebot/dcos,xinxian0458/dcos,surdy/dcos,mellenburg/dcos,vishnu2kmohan/dcos,lingmann/dcos,darkonie/dcos,branden/dcos,mnaboka/dcos,mesosphere-mergebot/mergebot-test-dcos,mellenburg/dcos,GoelDeepak/dcos,amitaekbote/dcos,asridharan/dcos,mesosphere-mergebot/mergebot-test-dcos,mnaboka/dcos,lingmann/dcos,mnaboka/dcos,kensipe/dcos,mesosphere-mergebot/dcos,dcos/dcos,mellenburg/dcos,mellenburg/dcos,branden/dcos,amitaekbote/dcos,asridharan/dcos,kensipe/dcos,mesosphere-mergebot/dcos,BenWhitehead/dcos,kensipe/dcos,jeid64/dcos,amitaekbote/dcos,asridharan/dcos,BenWhitehead/dcos,vishnu2kmohan/dcos,dcos/dcos,amitaekbote/dcos,darkonie/dcos