modified Travis' definition as in node-red project

[KatsuyaHoshii]

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

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

Proposed changes

Describe the nature of this change. What problem does it address?

Checklist

Put an x in the boxes that apply

• 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 decreased (-35.2%) to 42.374% when pulling 6de6a33 on node-red-hitachi:master-update-travis-definition into d174103 on node-red:master.