Fix some easy warnings

release.sh

@@ -25,8 +25,8 @@ echo "Please provide a version number on the form 'v1.2.3' for the new release:"
 read -r VERSION
 
 # https://github.com/walles/moar/issues/47
-if ! echo "$VERSION" | grep -q -E '^v[0-9]+\.[0-9]+\.[0-9]+$'; then
-  echo "ERROR: Version number must be on the form: v1.2.3: $VERSION"
+if ! echo "${VERSION}" | grep -q -E '^v[0-9]+\.[0-9]+\.[0-9]+$'; then
+  echo "ERROR: Version number must be on the form: v1.2.3: ${VERSION}"
   exit 1
 fi
 
@@ -36,12 +36,12 @@ echo
 
 # FIXME: Make this part of the editable tagging message
 echo "Changes since last release:"
-git log --first-parent --pretty="format:* %s" "$LAST_VERSION"..HEAD | sed 's/ diff.*//'
+git log --first-parent --pretty="format:* %s" "${LAST_VERSION}"..HEAD | sed 's/ diff.*//'
 echo
 echo
 
 # Make an annotated tag for this release
-git tag --annotate "$VERSION"
+git tag --annotate "${VERSION}"
 
 # NOTE: To get the version number right, these builds must be done after the
 # above tagging.
@@ -57,11 +57,11 @@ git push --tags
 # FIXME: Instead of asking the user to upload the binaries, upload them for
 # the user.
 echo
-echo "Please upload the following binaries to <https://github.com/walles/moar/releases/tag/$VERSION>:"
-file releases/moar-"$VERSION"-*-*
+echo "Please upload the following binaries to <https://github.com/walles/moar/releases/tag/${VERSION}>:"
+file releases/moar-"${VERSION}"-*-*
 
 echo
 echo "Also, update the brew packaging by making a PR to this file:"
 echo "https://github.com/Homebrew/homebrew-core/blob/master/Formula/moar.rb"
 echo
-echo "brew bump-formula-pr --url=https://github.com/walles/moar/archive/refs/tags/$VERSION.tar.gz moar"
+echo "brew bump-formula-pr --url=https://github.com/walles/moar/archive/refs/tags/${VERSION}.tar.gz moar"