Add bump version script

TODO

@@ -2,7 +2,6 @@ Before new_layout branch merge
 ==============================
 * README.md update (pull-request #145)
 * Script to automatically update file contents:
-    version         : ISSUE_TEMPLATE.md, version.py
     contributors    : AUTHORS
 
 

devscripts/bump-version.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+
+# Author: Sotiris Papadopoulos <ytubedlg@gmail.com>
+# Last-Revision: 2017-04-17
+# Script to bump the version and automatically update related files
+#
+# Usage: ./bump_version.sh <new-version>
+
+PACKAGE="youtube_dl_gui"
+
+FILES=`cat <<EOF
+$PACKAGE/version.py
+.github/ISSUE_TEMPLATE.md
+EOF`
+
+# Update version string on given file
+# $1 = current version
+# $2 = new version
+# $3 = file
+function update_version {
+    echo "Updating file: $3"
+    sed -i "s/$1/$2/g" $3
+}
+
+# Returns 'true' if given version is less or equal to the current version
+# $1 = version to check
+# $2 = current version
+function version_le {
+    smallest_version=`echo -e "$1\n$2" | sort -V | head -n1`
+    [ "$1" = "$smallest_version" ]
+}
+
+
+if [ $# -ne 1 ]; then
+    echo "Usage ./bump_version.sh <new-version>"
+    exit 1
+fi
+
+cd ..
+
+new_version=$1
+cur_version=`grep version "$PACKAGE/version.py" | cut -d"'" -f2`
+
+echo "Current version = $cur_version"
+echo "New version     = $new_version"
+echo
+
+if version_le $new_version $cur_version; then
+    echo "New version must be greater than the current version, exiting..."
+    exit 1
+fi
+
+for file in $FILES; do
+    update_version $cur_version $new_version $file
+done
+
+echo "Done"