* removed packer.Cache and references since packer.Cache is never used except in the download step. The download step now uses the new func packer.CachePath(targetPath) for this, the behavior is the same.
* removed download code from packer that was reimplemented into the go-getter library: progress bar, http download restart, checksuming from file, skip already downloaded files, symlinking, make a download cancellable by context.
* on windows if packer is running without symlinking rights and we are getting a local file, the file will be copied instead to avoid errors.
* added unit tests for step_download that are now CI tested on windows, mac & linux.
* files are now downloaded under cache dir `sha1(filename + "?checksum=" + checksum) + file_extension`
* since the output dir is based on the source url and the checksum, when the checksum fails, the file is auto deleted.
* a download file is protected and locked by a file lock,
* updated docs
* updated go modules and vendors
Run now takes a context as well as a statebag. We'll assign the context
to the blank identifier to prevent namespace collisions. We'll let the
step authors opt-in to using the context.
`find . -iname "step_*.go" -exec gsed -i'' 's/func \(.*\)Run(/func \1Run(_ context.Context, /' {} \;`
Ensure that all builders include FloppyDirectories in the StepCreateFloppy options.
Changed the way the unit-tests in common/step_create_floppy_test work to use the static test-fixtures directory instead of creating the paths dynamically.
Removed a duplicate line of documentation from parallels-pvm.html.md that occurred during rebasing.
When debugging a build (or maintaining an existing packer file), teach `packer build -debug` how to step through individual `boot_command`s in order to triage the packer template.
Megan Marsh
Adrien Delorme
Rickard von Essen
Matthew Hooker
Josh Soref
Mikhail Zholobov
Ali Rizvi-Santiago
Orivej Desh
Ricard Clau
Sean Chittenden