Removed need for matplotlibs 538 style.

I got the original code from the author, Cameron Davidson-Pilon,
modified it for the minor changes I make for the book, and put it
in 538.json. The main gain is that somebody doesn't need bleeding
edge matplotlib installed to get the 538 look.

code/538.json

@@ -0,0 +1,40 @@
+{
+  "lines.linewidth": 2.0,
+  "examples.download": true,
+  "patch.linewidth": 0.5,
+  "legend.fancybox": true,
+  "axes.color_cycle": [
+    "#30a2da",
+    "#fc4f30",
+    "#e5ae38",
+    "#6d904f",
+    "#8b8b8b"
+  ],
+  "axes.facecolor": "#f0f0f0",
+  "axes.labelsize": "large",
+  "axes.axisbelow": true,
+  "axes.grid": true,
+  "patch.edgecolor": "#f0f0f0",
+  "axes.titlesize": "x-large",
+  "svg.embed_char_paths": "path",
+  "examples.directory": "",
+  "figure.facecolor": "#f0f0f0",
+  "grid.linestyle": "-",
+  "grid.linewidth": 1.0,
+  "grid.color": "#cbcbcb",
+  "axes.edgecolor":"#f0f0f0",
+  "xtick.major.size": 0,
+  "xtick.minor.size": 0,
+  "ytick.major.size": 0,
+  "ytick.minor.size": 0,
+  "axes.linewidth": 3.0,
+  "font.size":14.0,
+  "lines.linewidth": 2,
+  "lines.solid_capstyle": "butt",
+  "savefig.edgecolor": "#f0f0f0",
+  "savefig.facecolor": "#f0f0f0",
+  "figure.subplot.left"    : 0.08,
+  "figure.subplot.right"   : 0.95, 
+  "figure.subplot.bottom"  : 0.07,
+  "figure.subplot.hspace"  : 0.5
+}