Use a more descriptive subject

Also removes the unnecessary (and now broken in 2.0) checks for
respond_to? on accessors.

spec/lib/rex/post/meterpreter/packet_parser_spec.rb

@@ -4,7 +4,7 @@ require 'rex/post/meterpreter/packet_parser'
 
 
 describe Rex::Post::Meterpreter::PacketParser do
-  subject{
+  subject(:parser){
     Rex::Post::Meterpreter::PacketParser.new
   }
   before(:each) do
@@ -18,41 +18,17 @@ describe Rex::Post::Meterpreter::PacketParser do
     end
   end
 
-  it "should respond to cipher" do
-    subject.should respond_to :cipher
-  end
-
-  it "should respond to raw" do
-    subject.should respond_to :raw
-  end
-
-  it "should respond to reset" do
-    subject.should respond_to :reset
-  end
-
-  it "should respond to recv" do
-    subject.should respond_to :recv
-  end
-
-  it "should respond to hdr_length_left" do
-    subject.should respond_to :hdr_length_left
-  end
-
-  it "should respond to payload_length_left" do
-    subject.should respond_to :payload_length_left
-  end
-
   it "should initialise with expected defaults" do
-    subject.send(:raw).should == ""
-    subject.send(:hdr_length_left).should == 8
-    subject.send(:payload_length_left).should == 0
+    parser.send(:raw).should == ""
+    parser.send(:hdr_length_left).should == 8
+    parser.send(:payload_length_left).should == 0
   end
 
   it "should parse valid raw data into a packet object" do
     while @raw.length >0
-      parsed_packet = subject.recv(@sock)
+      parsed_packet = parser.recv(@sock)
     end
-    parsed_packet.class.should == Rex::Post::Meterpreter::Packet
+    parsed_packet.should be_a Rex::Post::Meterpreter::Packet
     parsed_packet.type.should == Rex::Post::Meterpreter::PACKET_TYPE_REQUEST
     parsed_packet.method?("test_method").should == true
   end