fix upgrade script not finding ohmyzsh

dot_scripts/upgrade.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env zsh
 export SDKMAN_DIR="$HOME/.sdkman"
 [[ -s "$SDKMAN_DIR/bin/sdkman-init.sh" ]] && source "$SDKMAN_DIR/bin/sdkman-init.sh"
 sdk selfupdate
@@ -8,7 +9,7 @@ brew outdated | xargs brew upgrade
 bundle update --all
 #gem update --system
 #gem update asciidoctor-pdf t
-upgrade_oh_my_zsh
+zsh ~/.oh-my-zsh/tools/upgrade.sh
 npm update -g jira-node-cli --save
 sudo pip install --upgrade pip
 sudo pip3 install --upgrade pip