Skip dependency check for lockfile

.gitignore

@@ -1,2 +1,3 @@
 src/
-bin/
+bin/
+.dependencies

openwrtbuilder

@@ -205,6 +205,7 @@ installDependencies() {
     debug "${FUNCNAME[0]}"
 
     declare -a pkg_list
+    declare lock_file="$BUILDROOT/.dependencies"
 
     # TODO please contribute your platform here
     if (( FROM_SOURCE )); then
@@ -349,7 +350,11 @@ installDependencies() {
         esac
     fi
 
-    pkg_install "${pkg_list[@]}"
+    # Skip dependency installation if lock file is present
+    [[ -f $lock_file ]] && return
+        
+    pkg_install "${pkg_list[@]}" && echo "${pkg_list[@]}" > "$lock_file"
+    
 }