Add code snippet to rerun Axelrod's second tournament to readme

Author: marcharper

README.rst

@@ -18,15 +18,36 @@ Installation
 Usage
 =====
 
-::
+Running a match:
+
+.. code-block:: python
+
+   >>> import axelrod_fortran as axlf
+   >>> import axelrod as axl
+   >>> p1 = axlf.Player('k31r')
+   >>> p2 = axlf.Player('k33r')
+   >>> match = axl.Match((p1, p2), turns=5)
+   >>> match.play()
+   [(C, C), (C, C), (C, D), (C, D), (C, C)]
+
+Reproducing Axelrod's second tournament:
+
+.. code-block:: python
+
+   import axelrod as axl
+   from axelrod_fortran.strategies import characteristics
+   from axelrod_fortran.player import Player
+
+   players = [Player(name) for name in characteristics.keys()
+              if characteristics[name]["original_rank"] is not None]
+
+   print(len(players), "players")
 
-    >>> import axelrod_fortran as axlf
-    >>> import axelrod as axl
-    >>> p1 = axlf.Player('k31r')
-    >>> p2 = axlf.Player('k33r')
-    >>> match = axl.Match((p1, p2), turns=5)
-    >>> match.play()
-    [(C, C), (C, C), (C, D), (C, D), (C, C)]
+   tournament = axl.Tournament(players, repetitions=100)
+   results = tournament.play(processes=4)
+   results.write_summary('summary.csv')
+   plot = axl.Plot(results)
+   plot.save_all_plots("second_tournament")
 
 Contributing
 ============

src/axelrod_fortran/player.py

@@ -3,7 +3,6 @@
 import axelrod as axl
 from axelrod.interaction_utils import compute_final_score
 from axelrod.action import Action
-from axelrod import Game
 from ctypes import cdll, c_int, c_float, byref, POINTER
 from .strategies import characteristics
 
@@ -49,7 +48,7 @@ def original_name(self, value):
         if value in characteristics:
             self.__original_name = value
         else:
-            raise ValueError(f'{value} is not a valid Fortran function')
+            raise ValueError('{} is not a valid Fortran function'.format(value))
 
     @property
     def original_function(self):