Don't use Object.assign because Node 0.12.x.
Don't use Object.assign because Node 0.12.x.

peernohell/node-slack-client,slackapi/node-slack-sdk,peernohell/node-slack-client,slackhq/node-slack-client,slackhq/node-slack-sdk,slackapi/node-slack-sdk,slackapi/node-slack-sdk,slackapi/node-slack-sdk