ignore chart dependencies

[eyarz]

Is your feature request related to a problem? Please describe.
Today, if I will ran datree to test a chart with dependencies (that are not installed), I will get the following error message:
Error: An error occurred while checking for chart dependencies. You may need to run 'helm dependency build' to fetch missing dependencies: found in Chart.yaml, but missing in charts/ directory [CHART_NAME]

Describe the solution you'd like
A flag to skip pre-installed dependencies requirement: helm datree test [CHART_DIRECTORY] --ignore-dependencies
--ignore-dependencies -> this flag is just an example.

Describe alternatives you've considered
Comment out dependencies section from Chart:

Additional context

• Default behavior - include testing dependencies
• If missing dependencies message is raised - suggest the user to use the flag