chore: add `distclean` target to Makefile (#971)
chore: add `distclean` target to Makefile (#971)

This new target also deletes the `node_modules` and `bower_components`
directories, taking the project directory to a totally pristine state.
resin-io/herostratus,resin-io/resin-etcher,resin-io/etcher,resin-io/herostratus,resin-io/resin-etcher,resin-io/etcher,resin-io/etcher,resin-io/etcher,resin-io/etcher