Added flat_prior.py for pymultinest.

imagine/priors/__init__.py

 # -*- coding: utf-8 -*-
 
 from prior import Prior
+from flat_prior import FlatPrior

imagine/priors/flat_prior/__init__.py

+# -*- coding: utf-8 -*-
+
+from flat_prior import FlatPrior

imagine/priors/flat_prior/flat_prior.py

+# -*- coding: utf-8 -*-
+
+from imagine.priors.prior import Prior
+
+
+class FlatPrior(Prior):
+    def __call__(self, cube, ndim, nparams):
+        return cube

imagine/priors/prior/__init__.py

+# -*- coding: utf-8 -*-
+
+from prior import Prior

imagine/priors/prior.py → imagine/priors/prior/prior.py

@@ -7,5 +7,5 @@ from keepers import Loggable
 
 class Prior(Loggable, object):
     @abc.abstractmethod
-    def __call__(self, parameters):
+    def __call__(self, cube, ndim, nparams):
         raise NotImplemented