Merge pull request #3 from Stratus3D/add_get_version_from_legacy_file_script

Add the first version of the get_version_from_legacy_file bash script.

bin/get_version_from_legacy_file

+#!/usr/bin/env bash
+
+get_legacy_version() {
+    current_directory=$1
+    ruby_version_file="$current_directory/.ruby-version"
+
+    # Get version from .ruby-version file. .ruby-version is used by rbenv and now rvm.
+    if [ -f $ruby_version_file ]; then
+        cat $ruby_version_file
+    fi
+}
+
+get_legacy_version $1