Update Javapoet to 1.6.1
Update Javapoet to 1.6.1

git commit: dfcf55e5fc3f29ac55847a19627f9f15d3aff370
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=119557171

AttwellBrian/dagger,cgruber/dagger,google/dagger,hansonchar/dagger,ze-pequeno/dagger,google/dagger,ronshapiro/dagger,AttwellBrian/dagger,ronshapiro/dagger,ze-pequeno/dagger,ze-pequeno/dagger,ravn/dagger,ronshapiro/dagger,ravn/dagger,hansonchar/dagger,dushmis/dagger,google/dagger,dushmis/dagger,cgruber/dagger,hansonchar/dagger,google/dagger,cgruber/dagger,ze-pequeno/dagger,ravn/dagger