About downloading/extracting the tarball

[niklaus0823]

When node-pre-gyp use needle module, it will download nothing into module_path, finally return downloading/extracting the tarball

node-pre-gyp/lib/install.js

Lines 27 to 35 in 590da56

	try {
	http_get.impl = require('request');
	http_get.type = 'request';
	log.warn("Using request for node-pre-gyp https download");
	} catch (e) {
	http_get.impl = require('needle');
	http_get.type = 'needle';
	log.warn("Using needle for node-pre-gyp https download");
	}

[niklaus0823]

grpc/grpc-node#880