<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def tag_and_push(context):
 """Tags your git repo with the new version number"""

    tag_option = '--annotate'
    if probe.has_signing_key(context):
        tag_option = '--sign'

    shell.dry_run(
        TAG_TEMPLATE % (tag_option, context.new_version, context.new_version),
        context.dry_run,
    )

    shell.dry_run('git push --tags', context.dry_run)