deprecate anonHttp fetchStrategy

[vdice]

With #590 the Shim resource now supports a much more fully-featured fetchStrategy via platforms, which supports configuring a list of all supported OS/arch-combo shim binaries and their locations.

This this in mind, I'm not sure there is much use for the older, anonHttp strategy with its one location field. Therefore, I propose we deprecate this, with intentions to fully remove by 1.0.0.

Please feel free to chime in here if you'd like to see anonHttp continue as a fetchStrategy.

Otherwise, we could:

1. In 0.2.0 (or next), add deprecation notices, noting it will be removed in 1.0.0 (when the finalization of the Shim CRD happens)
2. remove as part of 1.0.0