* move maps of plugins back in core
* go mod vendor
* more fixes
* fix imports
* Update core_test.go
* fix build
* more fixes
* more fixes
* up vendors after fixing sdk
* Update post_processor_mock.hcl2spec.go
* Leave implementatino of MapOf in the sdk for plugi tests
Other wise use the interface
* go mod tidy
* add MapOfDatasource type too
This add :
* discovery of `packer-plugin-*` binaries from the known folders and ask them to describe themselves
* tests
For testing: in go we create a bash script that in turn calls back to Go. I could not make the tests to work on windows and then would like to postpone testing this for when we know more about the finite layout of this feature. That is mainly: how things are going to work with init, versioning and such.
Sylvia Moss
Adrien Delorme
Megan Marsh