Adding locking mechanism.

build.sh

@@ -2,6 +2,10 @@
 
 source ~/.bashrc
 cd $(dirname $0)
+if [ -f aleta.lock ]; then
+    echo 'Deploy is running.';
+fi
+touch aleta.lock
 pushd aleta
 git fetch
 current_commit=$(git rev-parse HEAD)
@@ -21,5 +25,5 @@ if [ ! -e output/aleta.tar.gz ]; then
     echo "aleta.tar.gz not exists." 1>&2
     exit 1
 fi
-
+rm aleta.lock
 perl create_aleta_release.pl