Enable wheels CI scripts to run locally (#57)
Taking inspiration from #35 and #62
This PR adds / updates:
- `rapids-configure-sccache` (new) : configures sccache for CI/local,
with the intention being to remove this information from CI containers
- `rapids-date-string` (new) : configures date string
- `rapids-configure-conda-channels` (new) : modifies conda channels
based on build type
- `rapids-env-update` (modified) : calls the `rapids-configure-sccache`
- `rapids-prompt-local-repo-config` (new) : consolidates prompts for
users to configure repo information locally
- `rapids-download-wheels/conda-from-s3` (updated) : uses
`rapids-prompt-local-repo-config`
- `rapids-upload-wheels-to-s3` (modifed) : guards to ensure local builds
don't try to upload
