Add shell upgrade script

upgrade.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+# Upgrade script
+
+if [ $# -eq 0 ]
+  then
+      echo 'Pass new LimeSurvey Version tag:'
+      echo 'upgrade.sh 3.15.8+190130'
+      exit 1
+fi
+
+NEW_VERSION=$1
+
+grep -qc $NEW_VERSION apache/Dockerfile fpm/Dockerfile fpm-alpine/Dockerfile
+
+if [ $? -eq 0 ]
+   then
+       echo "Already at version ${NEW_VERSION}"
+       exit 0
+fi
+
+# Download, unzip and chmod LimeSurvey from official GitHub repository
+wget -P /tmp "https://github.com/LimeSurvey/LimeSurvey/archive/${NEW_VERSION}.tar.gz"
+SHA256_CHECKSUM=$(sha256 "${NEW_VERSION}.tar.gz")
+
+# Update lines in the files
+sed -r -i -e "s/[0-9]+(\.[0-9]+)+\+[0-9]+/$NEW_VERSION/" apache/Dockerfile fpm/Dockerfile fpm-alpine/Dockerfile
+sed -r -i -e "s/[A-Fa-f0-9]{64}/$SHA256_CHECKSUM/" apache/Dockerfile fpm/Dockerfile fpm-alpine/Dockerfile
+
+# After that, check and commit