New plugin git-svn installing git project

git-svn-clone-externals

plugins/git-svn/.gitignore

+git-svn-clone-externals

plugins/git-svn/git-svn.plugin.zsh

+
+if ! [ -d "$ZSH/plugins/git-svn/git-svn-clone-externals" ] ;then
+    git clone https://github.com/andrep/git-svn-clone-externals.git
+fi
+export PATH="$ZSH/plugins/git-svn/git-svn-clone-externals:$PATH"
+
+function git_svn_update {
+    (cd "$ZSH/plugins/git-svn/git-svn-clone-externals" && \
+        git pull origin master)
+}