Revert "less inference, more explicit types"
Revert "less inference, more explicit types"

This reverts commit e581ffa5421aee9b13c5eed99232dcdf55685b99.

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