The dep library was initially a self contained project, but doesn't have a community of users.
Keeping it in the main repo should reduce the maintenance burden and simplify dependency management for the project.
Moved all the go files from the top level directory into the cmd/ package.
Updated Makefile so that all the commands still work.
The common pattern in Go programs, and one we adapted with the addition with the mdmdctl binary is that binaries live in cmd/binary-name/binary-name.go while libraries live in folders at the top level.
Improves http debug logging by also logging the sent response.
Converts regular http logs to key-value format.
Changes the http server options to httputil.ListenAndServe, which is antended to be a standard
ListenAndServe method for all micromdm project.
Adds environment variables as configuration options for sensitive values.
Closes#196
