Explicit cast to int in Collocation.py..

This is very strange and should not be needed. Yet, this fixes #73, which popped up after updating some package.

Author: pancetta

pySDC/Collocation.py

@@ -74,7 +74,7 @@ def _GaussLegendre(M, a, b):
         """
         assert a <= b, 'Interval boundaries are corrupt, got %f and %f' % (a,b)
 
-        M = M - 1
+        M = int(M - 1)
         M1 = M + 1
         M2 = M + 2