use proxy to connect to slack api endpoint

[smb]

Hi,

would it be possible to respect / handle http_proxy / https_proxy environment variables?

i had to add 'proxy' => 'tcp://127.0.0.1:3128' to the $options["http"] array in Slack.hooks.php (which points to my local CNTLM to prevent authentification issues) to tell php / file_get_contents to use our corp. proxy.

An alternative would be the usage of curl which should automatically handle proxy environment variables.