feat(medusa): cart context (#201)

- Adds a context field to Cart
- context is automatically populated with ip + user agent
- context can be updated via POST /store/cart/:id or set when creating via POST /store/cart

packages/medusa/package.json

@@ -44,7 +44,7 @@
   },
   "peerDependencies": {
     "medusa-interfaces": "1.x",
-    "mongoose": "5.x"
+    "typeorm": "0.2.x"
   },
   "dependencies": {
     "@babel/plugin-transform-classes": "^7.9.5",
@@ -82,7 +82,6 @@
     "request-ip": "^2.1.3",
     "resolve-cwd": "^3.0.0",
     "scrypt-kdf": "^2.0.1",
-    "typeorm": "^0.2.29",
     "ulid": "^2.3.0",
     "uuid": "^8.3.1",
     "winston": "^3.2.1"