Fix model.fit argument order

Author: levimcclenny

examples/burgers-new.py

@@ -40,7 +40,7 @@ def f_model(u_model, x, t):
 model.compile(layer_sizes, f_model, Domain, BCs)
 
 # to reproduce results from Raissi and the SA-PINNs paper, train for 10k newton and 10k adam
-model.fit(newton_iter=10000, tf_iter=10000)
+model.fit(tf_iter=10000, newton_iter=10000)
 
 
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