Must set PYTHONPATH to include OPENRAM_HOME now.
Reorganizes subdirs as packages.
Rewrites unit tests to use packages.
Update README.md with instructions, dependencies etc.
Update sky130 module imports.
Change tech specific package from modules to custom.
Convert to use li layer in pgates.
Fix multifinger devices with li layers.
Simplify wordline driver input routing.
Fix power pin direction option update.
PEP8 cleanup
Changes to simplify metal preferred directions and pitches.
Split of control logic tests.