Bump checkout action version

[smorimoto]

No description provided.

[claassistantio]

All committers have signed the CLA.

[smorimoto]

Submodule option is no longer supported. (and the default depth is 1, so we don't need that option.)

[ry]

Is there some improvement? Checkout works fine and this looks more complex.

[smorimoto]

Here is the changelog. It certainly looks a bit complicated, but I don't think it's a bad idea to keep following the new version. and current CI configuration is already a bit complicated.
https://github.com/actions/checkout/releases/tag/v2.0.0

[lucacasonato]

Is there some improvement? Checkout works fine and this looks more complex.

Its apparently faster because it doesn't check out the entire history - only the commit that is actually being tested.

[hayd]

Best to wait til this is fixed in v2 (seems kinda crazy everyone would be copying this).
actions/checkout#81

[bartlomieju]

Thanks @imbsky, but we're gonna stick with v1 for now

[smorimoto]

2.1.0 has been released.
https://github.com/actions/checkout/releases/tag/v2.1.0