Make sure nvm-exec can use .nvmrc logic. Fixes #402, obviates #403.
diff --git a/nvm-exec b/nvm-exec
index dc6bfca..b78c967 100755
--- a/nvm-exec
+++ b/nvm-exec
@@ -4,12 +4,11 @@
 
 source "$DIR/nvm.sh"
 
-if [ ! "$NODE_VERSION" ]; then
-  echo 'NODE_VERSION not set'
-  exit 1
+if [ -n "$NODE_VERSION" ]; then
+  nvm use $NODE_VERSION || (echo "NODE_VERSION not set" && exit 127)
+else
+  nvm use || (echo "No .nvmrc file found" && exit 127)
 fi
 
-nvm use $NODE_VERSION
-
 exec $@