Adds `tethys start` and `tethys quickstart` commands

[shawncrawley]

Description

This code, once merged, will implement both the 'tethys start' and tethys quickstart commands. The tethys start command is just shorthand for tethys manage start. The tethys quickstart command is for first-time development tethys installations and enables users to get started with Tethys in three steps with no other prompts:

conda create -n tethys -c tethysplatform -c conda-forge micro-tethys-platform
conda activate tethys
tethys quickstart

The tethys quickstart command condenses steps 3-5 as documented in "Getting Started" down to this single command, with the additions of automatically installing "Hello World" application running in single app mode, opening the user's default browser to http://127.0.0.1:8000, and then starting the server.

The documentation for the "Getting Started" page has been updated herein to reflect this change.

Changes Made to Code:

• tethys_cli/start_commands.py - new file that is home to the core logic of tethys [quick]start commands
• tethys_cli/scaffold_commands.py - prefix argument was added to the tethys scaffold CLI command to allow a user to specify the full prefix path to the install location, rather than using the current working directory
• tethys_cli/install_commands.py - do_exit argument was added to the internal function of the tethys install command to specify whether exit() should be called at the end of the installation or not; in the case of tethys quickstart the script execution should not be killed after installing the new hello world app as it normally would be when running the tethys install via the command line. The script must go on to also start the tethys server
• tethys_cli/gen_commands.py - check_existence argument was added to the get_destination_path function that allows checking a file's existence to be ignored when generating a new file (I'm actually not sure we need this though...)
• tethys_cli/init.py - new start and quickstart subparsers added to tethys cli command
• docs/installation.rst - completely rewritten to both reflect the new tethys quickstart command, but also to reduce verbosity and cut to the chase in general
• docs/images/getting_started/hello_world_login.png - new screenshot used in the tutorial; it depicts the login page that will automatically open in the browser upon running tethys quickstart
• docs/images/getting_started/hello_world_app.png - new screenshot used in the tutorial; it depicts the "Hello World" app that users will see after logging into Tethys Portal for the first time.

Related

Additional Notes

Quality Checks

• [x] New code is 100% tested
• [x] Code has been formated
• [x] Code has been linted
• [ ] Docstrings for new methods have been added

[coveralls]

coverage: 99.936%. remained the same when pulling adad068e07c891d07cb8bc72733f402035a36aa8 on tethys-quickstart into fbf295d1886b42512f3df6895694b3fc8d1b7c04 on main.