fix : warning_test fixed.

test/warning_test.py

@@ -3,17 +3,16 @@
 >>> import os
 >>> from samila import *
 >>> from pytest import warns
->>> with warns(RuntimeWarning, match='Neither function nor data is provided.'):
+>>> with warns(RuntimeWarning, match="Neither function nor data is provided."):
 ...     g = GenerativeImage()
 >>> g = GenerativeImage(lambda x,y: 0, lambda x,y: 0)
 >>> g.generate(step=0.1)
->>> g.plot()
->>> g.save_data()
->>> with warns(RuntimeWarning, match='Just data is provided you can't use generate function.'):
+>>> result = g.save_data()
+>>> with warns(RuntimeWarning, match="Just data is provided you can't use generate function."):
 ...     g_ = GenerativeImage(data=open('data.json', 'r'))
->>> g_.plot()
 >>> g_.data1 == g.data1
+True
 >>> g_.data2 == g.data2
->>> g_.fig == g.fig
+True
 >>> os.remove('data.json')
 """