Change .travis.yml's language: minimal to shell. (#1771)
Change .travis.yml's language: minimal to shell. (#1771)

There is no minimal language and due to travis-ci/travis-ci#4895, it will fallback to ruby. shell should serve our usecase

Signed-off-by: bndw <61a42987bb3825596ed309c27942e55bd87982b4@gmail.com>
amalgam8/envoy,istio/envoy,fengli79/envoy,lyft/envoy,tdmackey/envoy,eklitzke/envoy,rlazarus/envoy,fengli79/envoy,lyft/envoy,lyft/envoy,envoyproxy/envoy,eklitzke/envoy,dnoe/envoy,envoyproxy/envoy-wasm,rlazarus/envoy,dnoe/envoy,envoyproxy/envoy,rlazarus/envoy,envoyproxy/envoy,lizan/envoy,sebrandon1/envoy,eklitzke/envoy,envoyproxy/envoy,craffert0/envoy,tdmackey/envoy,lizan/envoy,istio/envoy,envoyproxy/envoy-wasm,lizan/envoy,jrajahalme/envoy,dnoe/envoy,istio/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,dnoe/envoy,eklitzke/envoy,envoyproxy/envoy,tdmackey/envoy,lizan/envoy,istio/envoy,istio/envoy,amalgam8/envoy,sebrandon1/envoy,lyft/envoy,rlazarus/envoy,lizan/envoy,jrajahalme/envoy,fengli79/envoy,envoyproxy/envoy,lizan/envoy,envoyproxy/envoy,istio/envoy,amalgam8/envoy,jrajahalme/envoy,istio/envoy,eklitzke/envoy,craffert0/envoy,envoyproxy/envoy,jrajahalme/envoy,amalgam8/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,tdmackey/envoy,sebrandon1/envoy,lyft/envoy,craffert0/envoy,jrajahalme/envoy,fengli79/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,jrajahalme/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,sebrandon1/envoy,dnoe/envoy,craffert0/envoy,sebrandon1/envoy