feat: migrate to typescript, support 6.3.0+

- use babel to 7, update dependencies, fix #72
- proper babel build to support ngInject, fix #78
- proper buckets display in 6.3.0+, fix #76
- rename js to ts, build d3 lib as js, build src as ts

dist/libs/d3-scale-chromatic/colors.js

@@ -7,9 +7,12 @@ System.register([], function (_export, _context) {
     var n = specifier.length / 6 | 0,
         colors = new Array(n),
         i = 0;
+
     while (i < n) {
       colors[i] = "#" + specifier.slice(i * 6, ++i * 6);
-    }return colors;
+    }
+
+    return colors;
   });
 
   return {