require Artistic Style Version 2.05.1

Tools/fix_code_style.sh

@@ -1,4 +1,14 @@
 #!/bin/bash
+
+ASTYLE_VER=`astyle --version`
+ASTYLE_VER_REQUIRED="Artistic Style Version 2.05.1"
+
+if [ "$ASTYLE_VER" != "$ASTYLE_VER_REQUIRED" ]; then
+  echo "Error: you're using ${ASTYLE_VER}, but PX4 requires ${ASTYLE_VER_REQUIRED}"
+  echo "You can get the correct version here: https://github.com/PX4/astyle/releases/tag/2.05.1"
+  exit 1
+fi
+
 DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 astyle \
     --options=$DIR/astylerc          \