Add missing `set -e`

bin/rbenv-set-default

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 RBENV_VERSION="$1"
 if [ -z "$RBENV_VERSION" ]; then
   echo "usage: rbenv set-default VERSION" >&2

bin/rbenv-versions

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 RBENV_VERSION="$(rbenv-version)"
 
 for path in ~/.rbenv/versions/*; do