add compat-helper

[oscardssmith]

No description provided.

[mortenpi]

Not saying that this is a bad idea, but is there any particular motivation to add it right now? I am subscribed to a few repositories that use it, and I find it a little too noisy at times.

[oscardssmith]

I went through the 80 dependents of AbstractTrees to find package that didn't have compathelper and have dependents since we just tagged 0.4.

[serenity4]

Having compat helper would help avoid (or catch) some bugs related to version mismatches, see #59.

[MichaelHatherly]

Having compat helper would help avoid (or catch) some bugs related to version mismatches, see #59.

I had assumed, wrongly, that CompatHelper was running on this repo, otherwise I would have done that bump manually when I tagged 0.9.

I find it a little too noisy at times.

It might sometimes be a little noisy, but it does help automate a process that is otherwise quite messy if it needs to always be handled manually for every dep.

[mortenpi]

Fair points. It's actually easy to forget this repo, so that occasional noise is probably a good thing.

[mortenpi]

I went ahead and merged with the latest recommended version of the file. Thanks for raising this @oscardssmith!