Add naive cli command router

spec/command_router_spec.cr

@@ -0,0 +1,14 @@
+require "./spec_helper"
+require "../src/cli/*"
+
+describe CLI::CommandRouter do
+  it "should handle simple command" do
+    router = CLI::CommandRouter.new
+    x = 10
+    router.add "plus" do
+      x += 5
+    end
+    router.handle "plus"
+    x.should eq 15
+  end
+end

spec/resources_spec.cr

@@ -0,0 +1 @@
+require "./spec_helper"

src/cli/command_router.cr

@@ -0,0 +1,17 @@
+class CLI::CommandRouter
+  def initialize
+    @mappings = [] of {String, Proc(Nil)}
+  end
+
+  def add(route, &block)
+    @mappings.push({route, block})
+  end
+
+  def handle(command)
+    @mappings.each do |i|
+      if i[0] == command
+        i[1].call
+      end
+    end
+  end
+end