Drop request and request-promise deps

[rtfeldman]

See elm-lang/elm-platform#231 for motivation! This would drop about 4MB off every installer that uses it, which in turn would make them install faster. 🚀

This originally replaced request and request-promise with request-stream, which is more lightweight than either. It's a tiny wrapper around Node's built-in http and https modules which adds support for passing in URLs (Node's core lib requires separately specifying hostname, port, protocol, etc) and for following redirects, and that's about it.

Then I took it a step further and removed request-stream in favor of directly using the built-in http and https modules. This has the downside of not following redirects, but it's not much work (or much code) to re-add support for that if it seems important. (I defaulted to assuming it's not, based on how binwrap is used in practice.)

Here are the dependencies post-PR:

├── mustache@2.3.0
├─┬ tar@2.2.1
│ ├─┬ block-stream@0.0.9
│ │ └── inherits@2.0.3 deduped
│ ├─┬ fstream@1.0.11
│ │ ├── graceful-fs@4.1.11
│ │ ├── inherits@2.0.3 deduped
│ │ ├── mkdirp@0.5.1 deduped
│ │ └─┬ rimraf@2.6.2
│ │   └─┬ glob@7.1.2
│ │     ├── fs.realpath@1.0.0
│ │     ├─┬ inflight@1.0.6
│ │     │ ├── once@1.4.0 deduped
│ │     │ └── wrappy@1.0.2
│ │     ├── inherits@2.0.3 deduped
│ │     ├─┬ minimatch@3.0.4
│ │     │ └─┬ brace-expansion@1.1.11
│ │     │   ├── balanced-match@1.0.0
│ │     │   └── concat-map@0.0.1
│ │     ├─┬ once@1.4.0
│ │     │ └── wrappy@1.0.2 deduped
│ │     └── path-is-absolute@1.0.1
│ └── inherits@2.0.3
└─┬ unzip-stream@0.3.0
  ├─┬ binary@0.3.0
  │ ├── buffers@0.1.1
  │ └─┬ chainsaw@0.1.0
  │   └── traverse@0.3.9
  └─┬ mkdirp@0.5.1
    └── minimist@0.0.8

I recommend viewing this PR with ?w=1.

[avh4]

As discussed elsewhere, I think we ought to continue to support redirects.

[rtfeldman]

@avh4 Added redirect logic (it will follow up to 10 redirects; easy to adjust if desired) and some tests!

"Added redirect logic"

[avh4]

I tried fixing the merge conflicts and got a failing test now:

  1) binwrap
       passes tests when specified URLs do exist:
     ChildProcessError: Command failed: (cd test_app && npm test)
TypeError: Cannot read property 'on' of undefined
    at /Users/avh4/workspace/binwrap/test.js:61:17
    at new Promise (<anonymous>)
    at /Users/avh4/workspace/binwrap/test.js:58:18
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:745:11)
    at startup (internal/bootstrap/node.js:279:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:696:3)
npm ERR! Test failed.  See above for more details.
 `(cd test_app && npm test)` (exited with error code 1)
      at callback (node_modules/child-process-promise/lib/index.js:33:27)
      at ChildProcess.exithandler (child_process.js:296:5)
      at maybeClose (internal/child_process.js:962:16)
      at Process.ChildProcess._handle.onexit (internal/child_process.js:251:5)

[lydell]

Do we need to “handle HTTPS_PROXY and NO_PROXY for people with corporate firewalls”?

elm/compiler@41ec49e#diff-234dbb95568376fa69c8c8f02316f97a

EDIT: Interesting module: https://github.com/gajus/global-agent
EDIT2: That module is 1.12MB…
EDIT3: What if we spawned curl instead? curl (and tar!) is available on Windows these days. We could fall back to wget on Linuxes without curl.