Update conda building block version handling and default value

[samcmill]

Pull Request Description

Update the conda building block to handle the new version number format (X.Y.Z-P).

Also update the default version to the current latest.

Fix #455.

Author Checklist

• [x] Updated documentation (pydocmd generate) if any docstrings have been modified
• [x] Passes all unit tests

[samcmill]

@scal444

[scal444]

Awesome, thanks!