👷 Run build against latest Node.js and MongoDB

This change adds a build run for Node.js v16, which was
[released in April][1].

We also run MongoDB tests against the latest version of MongoDB, since
v3.6 was [end-of-lifed in April][2].

[1]: https://nodejs.org/en/about/releases/
[2]: https://www.mongodb.com/support-policy

Author: alecgibson

.github/workflows/test.yml

@@ -18,9 +18,10 @@ jobs:
         - 10
         - 12
         - 14
+        - 16
     services:
       mongodb:
-        image: mongo:3.6
+        image: mongo:4.4
         ports:
         - 27017:27017
     timeout-minutes: 10

scripts/test-sharedb-mongo.sh

@@ -3,6 +3,6 @@
 cd ../
 git clone https://github.com/share/sharedb-mongo.git
 cd sharedb-mongo
-npm install
 npm install ../sharedb
+npm install
 npm test