[FEATURE]: Rename buildtest buildspec edit

[shahzebsiddiqui]

Please describe your feature request

Let's rename buildtest buildspec edit to buildtest buildspec edit-test

• Update option in https://github.com/buildtesters/buildtest/blob/devel/buildtest/cli/__init__.py
• Update bash completion https://github.com/buildtesters/buildtest/blob/devel/bash_completion.sh
• Update the user documentation https://github.com/buildtesters/buildtest/blob/devel/docs/gettingstarted/buildspecs_interface.rst#editing-buildspecs-in-your-preferred-editor
• Add regression test for https://app.codecov.io/gh/buildtesters/buildtest/blob/devel/buildtest/cli/buildspec.py or ignore the method during coverage result using exclude_lines see https://coverage.readthedocs.io/en/latest/excluding.html

Post question in Slack

• I agree that I posted my question in slack before creating this issue

Is there an existing issue

• I confirm there is no existing issue for this issue