removed explicit float cast for adam algorithm

Author: Yurii Shevchuk

neupy/algorithms/gd/adam.py

@@ -85,10 +85,10 @@ def init_param_updates(self, layer, parameter):
             value=asfloat(np.zeros(parameter_shape)),
         )
 
-        step = asfloat(self.variables.step)
-        beta1 = asfloat(self.beta1)
-        beta2 = asfloat(self.beta2)
-        epsilon = asfloat(self.epsilon)
+        step = self.variables.step
+        beta1 = self.beta1
+        beta2 = self.beta2
+        epsilon = self.epsilon
 
         gradient = T.grad(self.variables.error_func, wrt=parameter)