Fail on deploy errors

Deploys have been failing :-/ https://travis-ci.org/whatwg/streams/builds/43789094#L1383

deploy.sh

@@ -36,16 +36,16 @@ npm install -g scp2
 
 for f in out/*; do
     # Deploy to the commit snapshot location
-    scp2 $f $DESTINATION:$WEB_ROOT/$COMMITS_DIR/$SHA/
+    scp2 $f $DESTINATION:$WEB_ROOT/$COMMITS_DIR/$SHA/ || exit 1
     echo "Deployed $f to /$COMMITS_DIR/$SHA/"
 
     if [ $BRANCH != "master" ] ; then
         # Deploy to the branch snapshot location, if not master
-        scp2 $f $DESTINATION:$WEB_ROOT/$BRANCHES_DIR/$BRANCH/
+        scp2 $f $DESTINATION:$WEB_ROOT/$BRANCHES_DIR/$BRANCH/ || exit 1
         echo "Deployed $f to /$BRANCHES_DIR/$BRANCH/"
     else
         # Deploy master to the root
-        scp2 $f $DESTINATION:$WEB_ROOT/
+        scp2 $f $DESTINATION:$WEB_ROOT/ || exit 1
         echo "Deployed $f to /"
     fi
 done