Only look for moderate and above vulnerabilities (#201)

There's currently a low-level vulnerability that's blocking all builds

client/Dockerfile

@@ -12,7 +12,7 @@ RUN npm install
 
 # Check linting
 RUN npm run lint
-RUN npm audit
+RUN npm audit --audit-level=moderate
 
 # Build assets
 RUN NODE_ENV=production npm run build