Update babel dependency for security issues

.babelrc

@@ -1,5 +1,5 @@
 {
   "presets": [
-    "es2015"
+    "@babel/preset-env"
   ]
 }

build/index.js

@@ -3,20 +3,30 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-
-var _slicedToArray = function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; }();
+exports["default"] = void 0;
 
 var _kefir = require("kefir");
 
+function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _nonIterableRest(); }
+
+function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance"); }
+
+function _iterableToArrayLimit(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }
+
+function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
+
 var NEVER = _kefir.Kefir.never();
+
 var ZERO = _kefir.Kefir.constant(0);
 
 var ADD1 = function ADD1(x) {
   return x + 1;
 };
+
 var SUBTRACT1 = function SUBTRACT1(x) {
   return x - 1;
 };
+
 var ALWAYS = function ALWAYS(x) {
   return function () {
     return x;
@@ -32,7 +42,6 @@ var delay = function delay(n, s) {
     return i;
   });
 };
-
 /**
  * @typedef {Object} Galvo
  * @property {Kefir.Stream} current - Stream emitting the current item of the
@@ -67,15 +76,17 @@ var delay = function delay(n, s) {
  *   cycle.previous.log();
  *   // => ----a---b---c
  */
+
+
 function galvo(_ref3, collection) {
   var _ref3$advance = _ref3.advance,
-      advance = _ref3$advance === undefined ? NEVER : _ref3$advance,
+      advance = _ref3$advance === void 0 ? NEVER : _ref3$advance,
       _ref3$recede = _ref3.recede,
-      recede = _ref3$recede === undefined ? NEVER : _ref3$recede,
+      recede = _ref3$recede === void 0 ? NEVER : _ref3$recede,
       _ref3$index = _ref3.index,
-      index = _ref3$index === undefined ? ZERO : _ref3$index;
-
+      index = _ref3$index === void 0 ? ZERO : _ref3$index;
   var length = collection.length;
+
   var applyT = function applyT(i, transform) {
     return (transform(i) + length) % length;
   };
@@ -87,6 +98,7 @@ function galvo(_ref3, collection) {
     return SUBTRACT1;
   });
   var indexT = index.map(ALWAYS);
+
   var transformations = _kefir.Kefir.merge([nextT, previousT, indexT]);
 
   var currentIndex = transformations.scan(applyT, 0).takeWhile(function () {
@@ -95,10 +107,8 @@ function galvo(_ref3, collection) {
   var current = currentIndex.map(function (i) {
     return collection[i];
   });
-
   var previousIndex = delay(1, currentIndex);
   var previous = delay(1, current);
-
   return {
     current: current,
     currentIndex: currentIndex,
@@ -107,4 +117,5 @@ function galvo(_ref3, collection) {
   };
 }
 
-exports.default = galvo;
+var _default = galvo;
+exports["default"] = _default;