Removed mpl.use('TkAgg') as it is not needed to make newer versions o…

…f matplotlib on OS X

ludwig/utils/visualization_utils.py

@@ -22,16 +22,14 @@
 from collections import Counter
 
 import matplotlib as mpl
-from matplotlib import ticker
-from matplotlib.lines import Line2D
-
-mpl.use('TkAgg')  # make matplotlib run on mac os
 import matplotlib.patches as patches
 import matplotlib.path as path
 import matplotlib.patheffects as PathEffects
 import matplotlib.pyplot as plt
 import numpy as np
 import seaborn as sns
+from matplotlib import ticker
+from matplotlib.lines import Line2D
 from mpl_toolkits.mplot3d import Axes3D
 
 

requirements.txt

@@ -1,6 +1,6 @@
 Cython>=0.25
 h5py>=2.6
-matplotlib>=2.0
+matplotlib>=3.0
 numpy>=1.12,<1.16
 pandas>=0.19
 scipy>=0.18