Add error bundling to help deal with high traffic

[robbieaverill]

Original pull request from #93 had the following points:

Updates

• Add a bundler class which populates an array with incoming messages
• Send a bundle after certain conditions have been met. Either the number of messages in the bundle reaches the maximum bundle size (default 100) or after a time period (default 60s)
• Post bundle to the bundle entries endpoint on the API

@samuel-holt said on the PR: I would be interested in adding this bundling functionality but with a different approach, I think this PR is stale and should be deleted.

This issue can track a future enhancement to re-implement it again.