"Delete environment" command should fail without both project and environment parameters

Describe the bug
Running lagoon delete environment without specifying both project and environment auto-selects one or both based on your current working directory, and attempts to proceed with a deletion. (i.e. shows a confirmation dialog. I haven't tested with --force.)

To Reproduce
Steps to reproduce the behaviour:

1. Navigate to a lagoon-enabled repository
2. Run one of:
   • lagoon delete environment
   • lagoon -p project-name delete environment
   • lagoon -e environment-name delete environment
3. The cli offers to delete an environment, but not necessarily the one you intend
   • project appears to pull from the file specified by 'docker-compose-yaml' in .lagoon.yml
   • environment seems to use the current git branch name, even if there is no matching environment in a project

Expected behaviour
Unless both project and environment are explicitly provided, a high-impact command like delete should fail fast with a suitable usage message. Making any assumptions based on the current working directory is risky in this context.

Screenshots
N/A

Desktop (please complete the following information):

• OS: Linux
• Browser: N/A
• Version: lagoon 0.9.2 (go version go1.13.12 linux/amd64)

Additional context
As a related side note, the lagoon delete environment syntax feels like it could/should take the target as a direct parameter, e.g.:
lagoon -p project-name delete environment environment-name

That's what I first tried ― no error was thrown, but the environment was selected incorrectly. (Leading to this report.)