Simplify script

1. we now rely on $1's vendor.sh script (instead of duplicating it here)
2. we assume that hex_core is rebar3-compatible
3. we rely on TARGET_ERLANG_VERSION
4. we generate exactly what was previously generating, while targeting a specific Erlang/OTP vsn

vendor_hex_core.sh

@@ -6,61 +6,13 @@ if [[ -z "$1" ]]; then
   exit 1
 fi
 
-source_dir=$1/src
-target_dir=src/vendored
-prefix=r3_
-hex_core_version=`cat $source_dir/hex_core.hrl | grep HEX_CORE_VERSION | cut -d'"' -f2`
-
-filenames="hex_core.hrl \
-           hex_core.erl \
-           hex_erl_tar.erl \
-           hex_erl_tar.hrl \
-           hex_filename.erl \
-           hex_pb_names.erl \
-           hex_pb_package.erl \
-           hex_pb_signed.erl \
-           hex_pb_versions.erl \
-           hex_tarball.erl \
-           hex_registry.erl \
-           hex_http_httpc.erl \
-           hex_http.erl \
-           hex_repo.erl \
-           hex_api.erl \
-           hex_api_key.erl \
-           hex_api_package.erl \
-           hex_api_package_owner.erl \
-           hex_api_release.erl \
-           hex_api_user.erl \
-           safe_erl_term.xrl"
-
-search_to_replace="hex_core: \
-                   hex_core) \
-                   hex_core.hrl \
-                   hex_erl_tar \
-                   hex_filename \
-                   hex_pb_names \
-                   hex_pb_package \
-                   hex_pb_signed \
-                   hex_pb_versions \
-                   hex_registry \
-                   hex_tarball \
-                   hex_http \
-                   hex_repo \
-                   hex_api \
-                   safe_erl_term"
-
-rm -f $target_dir/$prefix*
-
-for filename in $filenames; do
-  source_path=$source_dir/$filename
-  target_path=$target_dir/$prefix$filename
-
-  echo "%% Vendored from hex_core v$hex_core_version, do not edit manually" > $target_path
-  echo >> $target_path
-  cat $source_path >> $target_path
-
-  for word in $search_to_replace; do
-    sed -i.bak s/$word/$prefix$word/g $target_path
-    rm $target_path.bak
-  done
-done
+REBAR3_TOP=$(pwd)
+export REBAR3_TOP
+pushd "$1"
+touch proto/* # force re-generation of protobuf elements
+TARGET_ERLANG_VERSION=19
+export TARGET_ERLANG_VERSION
+rebar3 as dev compile
+./vendor.sh src r3_
+find src -regex '.*r3_.*' -exec mv -f {} "$REBAR3_TOP/src" \;
+popd