Collapse CLIs and sequencers into one executable

[datamattsson]

Goals:

• Remove bash dependency
• Initialize templates and configuration into an empty directory
• Install as a Python CLI
• Single CLI for running and reporting
• Add profiles for a vendor-product convention (Preconfigured StorageClass and Secret template)

Examples:

# Create namespace and copy in base structure in current directory
$ benk init --profile=hpe-nimble

# Delete base and namespace
$ benk tidy

# Run and log a single overlay
$ benk run overlay

# Run and log a sequence
$ benk sequence mydirs-*

# Run and log a multi-cluster config
$ benk cluster mydirs-*

# Report a job, sequence or A/B 
$ benk report -f -l -a -g -s

This issue will be updated with more ideas before committing a design and implementation.