make Participant#amqp_connect overridable

Gemfile.lock

@@ -1,9 +1,10 @@
 GIT
   remote: git://github.com/jmettraux/ruote.git
-  revision: e5996817d09313ebc19b5586dbc9671f99d55420
+  revision: 75398e451bea4c269cdf24d61d3235b1b1b96519
   specs:
     ruote (2.3.0)
-      parslet (>= 1.2.3)
+      blankslate (>= 2.1.2.4)
+      parslet (>= 1.4.0)
       rufus-cloche (>= 1.0.2)
       rufus-dollar (>= 1.0.4)
       rufus-json (>= 1.0.1)
@@ -33,9 +34,9 @@ GEM
     blankslate (2.1.2.4)
     diff-lcs (1.1.3)
     eventmachine (0.12.10)
-    file-tail (1.0.10)
-      tins (~> 0.4.3)
-    parslet (1.3.0)
+    file-tail (1.0.11)
+      tins (~> 0.5.0)
+    parslet (1.4.0)
       blankslate (~> 2.0)
     rake (0.9.2.2)
     rspec (2.11.0)
@@ -66,7 +67,7 @@ GEM
       ruby2ruby (>= 1.2.5)
       ruby_parser (>= 2.0.5)
       sexp_processor (>= 3.0.5)
-    tins (0.4.3)
+    tins (0.5.3)
     tzinfo (0.3.33)
     yajl-ruby (1.1.0)
 

lib/ruote/amqp/participant.rb

@@ -260,7 +260,7 @@ def forget; opt('forget'); end
 
     # How a workitem is turned into an AMQP message payload (string).
     #
-    # Feel free to override this method to accomodate your needs.
+    # Feel free to override this method to accommodate your needs.
     #
     def encode_workitem
 
@@ -269,28 +269,31 @@ def encode_workitem
 
     # How a "cancelitem" is turned into an AMQP message payload (string).
     #
-    # Feel free to override this method to accomodate your needs.
+    # Feel free to override this method to accommodate your needs.
     #
     def encode_cancelitem
 
       Rufus::Json.encode(
         'cancel' => true, 'fei' => @fei.h, 'flavour' => @flavour)
     end
 
+    # Default AMQP.connect method.
+    #
+    # Feel free to override this method to accommodate your needs (See
+    # the README for an example).
+    #
+    def amqp_connect
+
+      AMQP.connect(Ruote.keys_to_sym(opt('connection') || {}))
+    end
+
     # Given connection options passed at registration time (when the
     # participant is registered in ruote) or from the process definition,
     # returns an AMQP::Channel instance.
     #
     def channel
 
-      Thread.current['_ruote_amqp_channel'] ||= begin
-
-        conn_opts = (opt('connection') || {}).each_with_object({}) { |(k, v), h|
-          h[k.to_sym] = v
-        }
-
-        AMQP::Channel.new(AMQP.connect(conn_opts))
-      end
+      Thread.current['_ruote_amqp_channel'] ||= AMQP::Channel.new(amqp_connect)
     end
 
     # Given exchange options passed at registrations time or from the process