StacVersion behind what's currently implemented

[jisantuc]

Describe the bug
There are two problems here -- the first problem is that stac4s doesn't really declare anywhere what version it supports. The second problem is that where it kind of sort of declares it, it's wrong -- we're in the 1.0.0 series, but ValidStacVersion still says 0.9.0 is the only valid one.

Expected behavior
Finding out STAC version isn't hard, validation is correct

Additional context
There aren't huge changes between 0.9.0 and 1.0.0-betaX, so this hasn't bitten us, but we should still update it and make it easier to discover. In particular, with Franklin reporting decoding errors to users, it would be nice if we didn't risk sending them to the wrong version of the STAC spec to fix things.

[jisantuc]

Bump, still bad, but now differently.