Support i18n in method name

[kazuhitoyokoi]

Types of changes

I fixed #25.

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

To refer to language files, I modified method names in Swagger node.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the mailing list/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage remained the same at 76.821% when pulling 0f635e4 on kazuhitoyokoi:master into 3dff818 on node-red:master.

[kazuhitoyokoi]

@HiroyasuNishiyama Could you check and merge the pull request?