Added cividis, a new colormap mathematically optimized while considering those with a color vision deficiency (#883)

Hi @jamienunez , thanks for this!

Author: jamienunez

Diff for: plotly/colors.py

@@ -202,7 +202,20 @@
         [0.7529411764705882, '#5ec962'], [0.8156862745098039, '#84d44b'],
         [0.8784313725490196, '#addc30'], [0.9411764705882353, '#d8e219'],
         [1, '#fde725']
+    ],
+    
+    'Cividis': [
+        [0.000000, 'rgb(0,32,76)'], [0.058824, 'rgb(0,42,102)'], 
+        [0.117647, 'rgb(0,52,110)'], [0.176471, 'rgb(39,63,108)'], 
+        [0.235294, 'rgb(60,74,107)'], [0.294118, 'rgb(76,85,107)'], 
+        [0.352941, 'rgb(91,95,109)'], [0.411765, 'rgb(104,106,112)'], 
+        [0.470588, 'rgb(117,117,117)'], [0.529412, 'rgb(131,129,120)'], 
+        [0.588235, 'rgb(146,140,120)'], [0.647059, 'rgb(161,152,118)'], 
+        [0.705882, 'rgb(176,165,114)'], [0.764706, 'rgb(192,177,109)'], 
+        [0.823529, 'rgb(209,191,102)'], [0.882353, 'rgb(225,204,92)'], 
+        [0.941176, 'rgb(243,219,79)'], [1.000000, 'rgb(255,233,69)']
     ]
+    
 }