Make the release script more resilient to new envs

scripts/release.sh

@@ -1,3 +1,4 @@
+set -e
 version=$(cat Cargo.toml | sed -n -e '/version/ {s/.* = *//p;q}' | tr -d '"')
 
 read -p "You wanted to release $version, right? [Y/n] " -n 1 -r
@@ -18,6 +19,10 @@ if ! command -v jq 2>&1 >/dev/null; then
     echo "Please install jq."
     exit 1
 fi
+if ! command -v docker 2>&1 >/dev/null; then
+    echo "Please install docker."
+    exit 1
+fi
 
 docker build -f build.Dockerfile -t lemur-build .
 MSYS_NO_PATHCONV=1 docker run -it --rm -v .:/app -w /app --entrypoint bash lemur-build /app/scripts/do-bundle.sh