Drop default MAXWIDTH to 3 (from 15) (#661)

* drop maxwidth from 15 to 5

* drop to 3

Author: ericphanson

src/Convex.jl

@@ -131,11 +131,11 @@ const MAXDEPTH = Ref(3)
 """
     MAXWIDTH
 
-Controls width of tree printing globally for Convex.jl; defaults to 15. Set via
+Controls width of tree printing globally for Convex.jl; defaults to 3. Set via
 
-    Convex.MAXWIDTH[] = 15
+    Convex.MAXWIDTH[] = 10
 """
-const MAXWIDTH = Ref(15)
+const MAXWIDTH = Ref(3)
 
 """
     MAXDIGITS