'prod' is a default name for target so renaming it into 'demo', so test scenarios won't be included in a release when amoc is used as a dependecy

unfortunately rebar3 doesn't copy any source files from the directories other than 'src' into release

   denysgonchar@Administrators-MacBook-Pro amoc % find . -name amoc_controller.erl
   ./_build/demo/rel/amoc/lib/amoc-2.2.0+build.788.refbccbc5d/src/amoc_controller.erl
   ./src/amoc_controller.erl
   denysgonchar@Administrators-MacBook-Pro amoc % find . -name parallel_throttle_test.erl
   ./scenarios/parallel_throttle_test.erl

and source code file is required for fetching edoc description for scenario.

So currently, we are not able to get 'doc' field of scenario info, when running amoc inside a container.

when we try to fetch info for parallel_throttle_test scenario:

   http://localhost:4000/scenarios/info/parallel_throttle_test

we get:

   {
     "doc": "no documentation found",
     "parameters": {
   ...

and at the same time the error is logger in amoc console:

   Attempt to process operation: 'ScenariosInfoIdGet'
   Source file for parallel_throttle_test is not available.

If you try to check manually the source file location using docsh_beam module, you get the following:

   (amoc@5441117ebf5d)1> {ok, B1} = docsh_beam:from_loaded_module(parallel_throttle_test).
   {ok,{docsh_beam,parallel_throttle_test,
                   "/home/amoc/amoc/lib/amoc-2.2.0+build.789.ref26c2eb1/ebin/parallel_throttle_test.beam",
                   false}}
   (amoc@5441117ebf5d)2> {ok, B2} = docsh_beam:from_loaded_module(amoc_controller).
   {ok,{docsh_beam,amoc_controller,
                   "/home/amoc/amoc/lib/amoc-2.2.0+build.789.reff907221/ebin/amoc_controller.beam",
                   "/home/amoc/amoc/lib/amoc-2.2.0+build.789.reff907221/src/amoc_controller.erl"}}

however, it's working fine if we preserve source files in the original location:

  (amoc@5441117ebf5d)1> {ok,B} = docsh_beam:from_loaded_module(parallel_throttle_test).
  {ok,{docsh_beam,parallel_throttle_test,
                  "/home/amoc/amoc/lib/amoc-2.2.0+build.789.reff907221/ebin/parallel_throttle_test.beam",
                  "/amoc_build/scenarios/parallel_throttle_test.erl"}}