Appmetrics 1.0.7 fails to install from github

[tunniclm]

When installing from github we see the following error during install:

Failed to gunzip: unexpected end of file

When trying to use appmetrics we see this error:

Failed to open library /home/tunniclm/Projects/appmetricstst/node_modules/appmetrics/libagentcore.so:/home/tunniclm/Projects/appmetricstst/node_modules/appmetrics/libagentcore.so: cannot open shared object file: No such file or directory
module.js:355
  Module._extensions[extension](this, filename);
                               ^
Error: Failed to initialize Agent Core library
    at Error (native)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/home/tunniclm/Projects/appmetricstst/node_modules/appmetrics/index.js:25:13)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)

This problem is introduced by PR #137 for issue #136 which changed the way files are downloaded to use the request package instead of http. This was intended to enable downloads from behind a proxy, however, the implementation was not correct and from that point on downloads would not work.

This only affected appmetrics installs from github (and not npm) since the download_all_binaries.js used in the npm package was not updated by #137 and still used the old download code.

[tunniclm]

Attached PR should fix download_licenses.js and download_binaries.js.
The download_all_binaries.js script used in the npm package should also be updated.

[tunniclm]

To clarify what PR #137 did incorrectly: it used request(url, function(err, response, body) {...}) and then tried to create a pipe from the request object.

However, this use of request() downloads the whole content of the download stream into the body variable, leaving the stream (which is part of the response object) empty. Therefore the pipe fails on the first read with "unexpected end of file".

The change in #160 changes the request() call to use the request(url) form which allows streaming via a call to pipe().

[hhellyer]

Thanks Mike, that makes sense of apparent refactoring fixing the problem - it's more than that it's using a different mechanism (despite being the same function name).