Update suggestion to keep using deprecated cookiecutter template

[r-b-g-b]

#162 uses ccds instead of cookiecutter. We want to have an informative message that instructs people who try to use cookiecutter to either a) switch to using ccds b) an option to continue using the deprecated cookiecutter. This PR simply adds that command.

cookiecutter https://...@v1

does not work

subprocess.CalledProcessError: Command '['git', 'clone', 'https://github.com/r-b-g-b/cookiecutter-data-science@v1']' returned non-zero exit status 128.

since git clone https://...@v1 fails.

Instead the cookiecutter docs state we can use

cookiecutter --help
  -c, --checkout TEXT        branch, tag or commit to checkout after git clone

I tested this out on my fork of this repo. I added a v1 tag on master and a v2 tag on new-cli.

cookiecutter https://github.com/r-b-g-b/cookiecutter-data-science -c v2

DEPRECATED [Use of the `cookiecutter` command is deprecated. Please use `ccds` in place of `cookiecutter`. To continue using the deprecated template, use `cookiecutter ... -c v1`.]:
Unable to create project directory '{{ cookiecutter.repo_name }}'
Error message: 'collections.OrderedDict object' has no attribute 'repo_name'
Context: {
    "cookiecutter": {
        "DEPRECATED": "Use of the `cookiecutter` command is deprecated. Please use `ccds` in place of `cookiecutter`. To continue using the deprecated template, use `cookiecutter ... -c v1`.",
        "_template": "https://github.com/r-b-g-b/cookiecutter-data-science"
    }
}

(Not sure what to do about the Error message: 'collections.OrderedDict object' has no attribute 'repo_name' @pjbull thoughts?)

ccds https://github.com/r-b-g-b/cookiecutter-data-science -c v2
You've downloaded /home/robert/.cookiecutters/cookiecutter-data-science before. Is it okay to delete and re-download it? [yes]: yes
project_name [project_name]:
repo_name [project_name]:
module_name [project_name]:
author_name [Your name (or your organization/company/team)]:
description [A short description of the project.]:
python_version_number [3.7]:
Select dataset_storage:
1 - none
2 - azure
3 - s3
4 - gcs
...

(When merge #162 to master and tag the previous version as v1, omitting the -c flag will default to the master branch as intended.)

[pjbull]

🙇 🙇 nice!