* Adds hadolint as pre-commit step
* Addresses all hadolint comments
* Use noninteractive apt-get frontend and clean after install
* dockerfile RUN statements are consolidated to prevent additional layers
* installed packages have pinned versions
* build(circleci): use speckle pre-commit runner with built-in hadolint
* Integrate pre-commit with husky bash script for git pre-commit hooks
* catches errors in bash
* if pre-commit is installed, it is run
* if optional additional binaries are installed, further pre-commit steps are run
* Update README with revised developer instructions
* Adds a pre-commit yarn script
Iain Sproat