chore: Enter pre-release mode and version packages

packages/medusa-plugin-slack-notification/package.json

@@ -1,6 +1,6 @@
 {
   "name": "medusa-plugin-slack-notification",
-  "version": "1.3.8",
+  "version": "1.3.9-rc.0",
   "description": "Slack notifications",
   "main": "index.js",
   "repository": {
@@ -23,7 +23,7 @@
     "client-sessions": "^0.8.0",
     "cross-env": "^5.2.1",
     "jest": "^25.5.4",
-    "medusa-interfaces": "^1.3.6"
+    "medusa-interfaces": "^1.3.7-rc.0"
   },
   "scripts": {
     "prepare": "cross-env NODE_ENV=production yarn run build",
@@ -32,15 +32,15 @@
     "watch": "babel -w src --out-dir . --ignore '**/__tests__','**/__mocks__'"
   },
   "peerDependencies": {
-    "medusa-interfaces": "1.3.6"
+    "medusa-interfaces": "1.3.7-rc.0"
   },
   "dependencies": {
     "@babel/plugin-transform-classes": "^7.9.5",
     "axios": "^0.19.2",
     "body-parser": "^1.19.0",
     "express": "^4.17.1",
-    "medusa-core-utils": "^1.1.39",
-    "medusa-test-utils": "^1.1.37",
+    "medusa-core-utils": "^1.2.0-rc.0",
+    "medusa-test-utils": "^1.1.40-rc.0",
     "moment": "^2.27.0"
   },
   "gitHead": "c46300d58fbfd0b2dc2c02745ae143e6247e885b",