feat(plugins/npm-post): add new plugin

plugins/npm-post.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+set -eu
+
+prepare() {
+  if [ "$(command -v GIT_PREPARE)" ]; then
+    GIT_PREPARE
+  fi
+}
+
+cleanup() {
+  if [ "$(command -v GIT_CLEANUP)" ]; then
+    GIT_CLEANUP
+  fi
+}
+
+release() {
+  # Commiting a `npm` tag
+  log "Commiting npm tag..."
+  log_verbose "Git hash: $CHECKOUT_SHA!"
+
+  if ! $IS_DRY_RUN; then
+    prepare
+
+    git add package.json
+
+    if $IS_WORKSPACE; then
+      git commit -m "Bump project ${PKG_NAME} version to ${NEXT_RELEASE_VERSION}"
+    else
+      git commit -m "Bump package.json version to ${NEXT_RELEASE_VERSION}"
+    fi
+
+    if [[ -n "$GIT_REMOTE_ORIGIN" ]]; then
+      git push
+      log_verbose "Pushed update to remote"
+    else
+      log_verbose "No Git remote to push tag"
+    fi
+
+    cleanup
+  else
+    log "Skipped commiting npm [$NEXT_RELEASE_TAG] tag in DRY-RUN mode."
+  fi
+}