fix travis.yml format
fix travis.yml format

ericvergnaud/antlr4,parrt/antlr4,parrt/antlr4,parrt/antlr4,ericvergnaud/antlr4,antlr/antlr4,parrt/antlr4,antlr/antlr4,parrt/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,parrt/antlr4,antlr/antlr4,ericvergnaud/antlr4,parrt/antlr4,parrt/antlr4,ericvergnaud/antlr4,parrt/antlr4,antlr/antlr4,antlr/antlr4,antlr/antlr4,parrt/antlr4,ericvergnaud/antlr4,antlr/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,antlr/antlr4,antlr/antlr4,antlr/antlr4,ericvergnaud/antlr4