drop global-tunnel-ng dependency

Author: mshima

lib/cli.js

@@ -15,16 +15,7 @@ const Router = require('./router');
 
 const gens = list(process.argv.slice(2));
 
-// Override http networking to go through a proxy ifone is configured
-const MAJOR_NODEJS_VERSION = Number.parseInt(process.version.slice(1).split('.')[0], 10);
-
-if (MAJOR_NODEJS_VERSION >= 10) {
-  // `global-agent` works with Node.js v10 and above.
-  require('global-agent').bootstrap();
-} else {
-  // `global-tunnel-ng` works only with Node.js v10 and below.
-  require('global-tunnel-ng').initialize();
-}
+require('global-agent').bootstrap();
 
 /* eslint new-cap: 0, no-extra-parens: 0 */
 const tabtab = new Tabtab.Commands.default({