Axios ES2017 (#4787)

* Added AxiosHeaders class;

* Fixed README.md href;

* Fixed a potential bug with headers normalization;

* Fixed a potential bug with headers normalization;
Refactored accessor building routine;
Refactored default transforms;
Removed `normalizeHeaderName` helper;

* Added `Content-Length` accessor;
Added missed `has` accessor to TS types;

* Added `AxiosTransformStream` class;
Added progress capturing ability for node.js environment;
Added `maxRate` option to limit the data rate in node.js environment;
Refactored event handled by `onUploadProgress` && `onDownloadProgress` listeners in browser environment;
Added progress & data rate tests for the http adapter;
Added response stream aborting test;
Added a manual progress capture test for the browser;
Updated TS types;
Added TS tests;
Refactored request abort logic for the http adapter;
Added ability to abort the response stream;

* Remove `stream/promises` & `timers/promises` modules usage in tests;

* Use `abortcontroller-polyfill`;

* Fixed AxiosTransformStream dead-lock in legacy node versions;
Fixed CancelError emitting in streams;

* Reworked AxiosTransformStream internal logic to optimize memory consumption;
Added throwing an error if the request stream was silently destroying (without error) Refers to #3966;

* Treat the destruction of the request stream as a cancellation of the request;
Fixed tests;

* Emit `progress` event in the next tick;

* Initial refactoring;

* Refactored Mocha tests to use ESM;

* Refactored Karma tests to use rollup preprocessor & ESM;
Replaced grunt with gulp;
Improved dev scripts;
Added Babel for rollup build;

* Added default commonjs package export for Node build;
Added automatic contributors list generator for package.json;

Co-authored-by: Jay <jasonsaayman@gmail.com>

gulpfile.js

@@ -0,0 +1,87 @@
+import gulp from 'gulp';
+import fs from 'fs-extra';
+import axios from './index.js';
+
+gulp.task('default', async function(){
+  console.log('hello!');
+});
+
+const clear = gulp.task('clear', async function() {
+  await fs.emptyDir('./dist/')
+});
+
+const bower = gulp.task('bower', async function () {
+  const npm = JSON.parse(await fs.readFile('package.json'));
+  const bower = JSON.parse(await fs.readFile('bower.json'));
+
+  const fields = [
+    'name',
+    'description',
+    'version',
+    'homepage',
+    'license',
+    'keywords'
+  ];
+
+  for (let i = 0, l = fields.length; i < l; i++) {
+    const field = fields[i];
+    bower[field] = npm[field];
+  }
+
+  await fs.writeFile('bower.json', JSON.stringify(bower, null, 2));
+});
+
+async function getContributors(user, repo, maxCount = 1) {
+  const contributors = (await axios.get(
+    `https://api.github.com/repos/${encodeURIComponent(user)}/${encodeURIComponent(repo)}/contributors?per_page=${maxCount}`
+  )).data;
+
+  return Promise.all(contributors.map(async (contributor)=> {
+    return {...contributor, ...(await axios.get(
+      `https://api.github.com/users/${encodeURIComponent(contributor.login)}`
+    )).data};
+  }))
+}
+
+const packageJSON = gulp.task('package', async function () {
+  const CONTRIBUTION_THRESHOLD = 3;
+
+  const npm = JSON.parse(await fs.readFile('package.json'));
+
+  try {
+    const contributors = await getContributors('axios', 'axios', 15);
+
+    npm.contributors = contributors
+      .filter(
+        ({type, contributions}) => type.toLowerCase() === 'user' && contributions >= CONTRIBUTION_THRESHOLD
+      )
+      .map(({login, name, url}) => `${name || login} (https://github.com/${login})`);
+
+    await fs.writeFile('package.json', JSON.stringify(npm, null, 2));
+  } catch (err) {
+    if (axios.isAxiosError(err) && err.response && err.response.status === 403) {
+      throw Error(`GitHub API Error: ${err.response.data && err.response.data.message}`);
+    }
+    throw err;
+  }
+});
+
+const env = gulp.task('env', async function () {
+  var npm = JSON.parse(await fs.readFile('package.json'));
+
+  await fs.writeFile('./lib/env/data.js', Object.entries({
+    VERSION: npm.version
+  }).map(([key, value]) => {
+    return `export const ${key} = ${JSON.stringify(value)};`
+  }).join('\n'));
+});
+
+const version = gulp.series('bower', 'env', 'package');
+
+export {
+  bower,
+  env,
+  clear,
+  version,
+  packageJSON
+}