added Rakefile for compilation

Rakefile

@@ -0,0 +1,15 @@
+
+def compile(filename)
+ `cd src; openscad -o ../print/#{filename}.stl #{filename}.scad`
+end
+
+task :default => :compile
+
+task :compile do
+  Dir.glob('src/*.scad') do |path|
+    puts "Compiling #{path}..."
+    filename = File.basename(path)[0..-(File.extname(path).length + 1)]
+    compile(filename)
+  end
+end
+