Fix up some examples (#3614)

examples/run_all.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -eu
+script_path=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
+cd "$script_path/"
+set -x
+
+for example_name in *; do
+    if [ -d "$example_name" ]; then
+        cargo run --quiet -p $example_name
+    fi
+done