Suppress output of `nvm use`

+redirect errors to stdout
diff --git a/nvm-exec b/nvm-exec
index b78c967..f40dd3a 100755
--- a/nvm-exec
+++ b/nvm-exec
@@ -5,9 +5,9 @@
 source "$DIR/nvm.sh"
 
 if [ -n "$NODE_VERSION" ]; then
-  nvm use $NODE_VERSION || (echo "NODE_VERSION not set" && exit 127)
+  nvm use $NODE_VERSION > /dev/null || (echo "NODE_VERSION not set" >&2 && exit 127)
 else
-  nvm use || (echo "No .nvmrc file found" && exit 127)
+  nvm use > /dev/null || (echo "No .nvmrc file found" >&2 && exit 127)
 fi
 
 exec $@