remove @babel/plugin-proposal-export-default-from (honestbleeps#4840)

Flow can't parse this syntax so we can't use it anyways.

Also, the equivalent syntax:
`export Foo from './foo'` -> `export { default as Foo } from './foo'`
isn't much longer and is clearer IMO (i.e. does the first one export something called `Foo` or the default export?)

.babelrc

@@ -1,6 +1,5 @@
 {
  "plugins": [
- "@babel/plugin-proposal-export-default-from",
  "@babel/plugin-proposal-export-namespace-from",
  ["@babel/plugin-proposal-class-properties", { "loose": true }],
  ["@babel/plugin-proposal-object-rest-spread", { "loose": true, "useBuiltIns": true }],

package.json

@@ -76,7 +76,6 @@
  "devDependencies": {
  "@babel/core": "7.0.0",
  "@babel/plugin-proposal-class-properties": "7.0.0",
- "@babel/plugin-proposal-export-default-from": "7.0.0",
  "@babel/plugin-proposal-export-namespace-from": "7.0.0",
  "@babel/plugin-proposal-object-rest-spread": "7.0.0",
  "@babel/plugin-transform-flow-strip-types": "7.0.0",

webpack.config.babel.js

@@ -74,7 +74,6 @@ export default (env = {}, argv = {}) => {
  loader: 'babel-loader',
  options: {
  plugins: [
- '@babel/plugin-proposal-export-default-from',
  '@babel/plugin-proposal-export-namespace-from',
  ['@babel/plugin-proposal-class-properties', { loose: true }],
  ['@babel/plugin-proposal-object-rest-spread', { loose: true, useBuiltIns: true }],

yarn.lock

@@ -269,13 +269,6 @@
  "@babel/helper-replace-supers" "^7.0.0"
  "@babel/plugin-syntax-class-properties" "^7.0.0"
 
-"@babel/[email protected]":
- version "7.0.0"
- resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-export-default-from/-/plugin-proposal-export-default-from-7.0.0.tgz#a057bbfd4649facfe39f33a537e18554bdd2b5da"
- dependencies:
- "@babel/helper-plugin-utils" "^7.0.0"
- "@babel/plugin-syntax-export-default-from" "^7.0.0"
-
 "@babel/[email protected]":
  version "7.0.0"
  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-export-namespace-from/-/plugin-proposal-export-namespace-from-7.0.0.tgz#ce847cc62c3626547107a1b835592b8ee494af51"
@@ -309,12 +302,6 @@
  dependencies:
  "@babel/helper-plugin-utils" "^7.0.0"
 
-"@babel/plugin-syntax-export-default-from@^7.0.0":
- version "7.0.0"
- resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-export-default-from/-/plugin-syntax-export-default-from-7.0.0.tgz#084b639bce3d42f3c5bf3f68ccb42220bb2d729d"
- dependencies:
- "@babel/helper-plugin-utils" "^7.0.0"
-
 "@babel/plugin-syntax-export-namespace-from@^7.0.0":
  version "7.0.0"
  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-export-namespace-from/-/plugin-syntax-export-namespace-from-7.0.0.tgz#17a7389a1d2571ac4d9b77ea2defa74a930edf5d"