[elm] Fix operations with empty responses (#171)

Author: eriktim

modules/openapi-generator/src/main/resources/elm/api.mustache

@@ -17,13 +17,13 @@ basePath =
 {-
    {{notes}}
 -}
-{{operationId}} : {{#pathParams}}{{dataType}} -> {{/pathParams}}{{#bodyParam}}{{dataType}} -> {{/bodyParam}}Http.Request {{#responses}}{{#-first}}{{^dataType}}(){{/dataType}}{{#isMapContainer}}(Dict.Dict String {{/isMapContainer}}{{#isListContainer}}(List {{/isListContainer}}{{dataType}}{{#isListContainer}}){{/isListContainer}}{{#isMapContainer}}){{/isMapContainer}}{{/-first}}{{/responses}}
+{{operationId}} : {{#pathParams}}{{dataType}} -> {{/pathParams}}{{#bodyParam}}{{dataType}} -> {{/bodyParam}}Http.Request {{^responses}}(){{/responses}}{{#responses}}{{#-first}}{{^dataType}}(){{/dataType}}{{#isMapContainer}}(Dict.Dict String {{/isMapContainer}}{{#isListContainer}}(List {{/isListContainer}}{{dataType}}{{#isListContainer}}){{/isListContainer}}{{#isMapContainer}}){{/isMapContainer}}{{/-first}}{{/responses}}
 {{operationId}} {{#pathParams}}{{paramName}} {{/pathParams}}{{#bodyParam}}model {{/bodyParam}}=
     { method = "{{httpMethod}}"
     , url = basePath ++ {{{path}}}
     , headers = []
     , body = {{#bodyParam}}Http.jsonBody <| {{vendorExtensions.x-encoder}} model{{/bodyParam}}{{^bodyParam}}Http.emptyBody{{/bodyParam}}
-    , expect = {{#responses}}{{#-first}}{{^dataType}}Http.expectStringResponse (\_ -> Ok ()){{/dataType}}{{#dataType}}Http.expectJson {{#isMapContainer}}(Decode.dict {{/isMapContainer}}{{#isListContainer}}(Decode.list {{/isListContainer}}{{#vendorExtensions}}{{x-decoder}}{{/vendorExtensions}}{{#isListContainer}}){{/isListContainer}}{{#isMapContainer}}){{/isMapContainer}}{{/dataType}}{{/-first}}{{/responses}}
+    , expect = {{^responses}}Http.expectStringResponse (\_ -> Ok ()){{/responses}}{{#responses}}{{#-first}}{{^dataType}}Http.expectStringResponse (\_ -> Ok ()){{/dataType}}{{#dataType}}Http.expectJson {{#isMapContainer}}(Decode.dict {{/isMapContainer}}{{#isListContainer}}(Decode.list {{/isListContainer}}{{#vendorExtensions}}{{x-decoder}}{{/vendorExtensions}}{{#isListContainer}}){{/isListContainer}}{{#isMapContainer}}){{/isMapContainer}}{{/dataType}}{{/-first}}{{/responses}}
     , timeout = Just 30000
     , withCredentials = False
     }