add initial Environment class

lib/rscons.rb

@@ -1,5 +1,2 @@
 require "rscons/version"
-
-module Rscons
-  # Your code goes here...
-end
+require "rscons/environment"

lib/rscons/environment.rb

@@ -0,0 +1,29 @@
+module Rscons
+  class Environment
+    class << self
+      alias_method :orig_new, :new
+    end
+
+    def self.new(*args)
+      e = Environment.orig_new(*args)
+      if block_given?
+        yield e
+        e.process
+      end
+      e
+    end
+
+    # Initialize a newly constructed Environment object
+    # === Arguments
+    # +variables+ _Hash_ ::
+    #   the variables hash can contain both construction variables, which are
+    #   uppercase strings (such as "CC" or "LDFLAGS"), and rscons options,
+    #   which are lowercase symbols (such as :echo).
+    def initialize(variables = {})
+      @variables = variables
+    end
+
+    def process
+    end
+  end
+end