Fix 500 Internal Error Internal Error when sending POST to Google APIs

[itskingori]

We are experience an error when trying to authenticate against Google OAuth2 with a "failed to load system roots and no roots provided" error.

I believe this is due to the lack of ca-certificates which might be breaking HTTPS/SSL connections.

2016/09/19 17:13:56 oauthproxy.go:125: mapping path "/" => upstream "http://upstream:5601"
2016/09/19 17:13:56 oauthproxy.go:152: OAuthProxy configured for Google Client ID: SOME_GOOGLE_CLIENT_ID
2016/09/19 17:13:56 oauthproxy.go:162: Cookie settings: name:_oauth2_proxy secure(https):true httponly:true expiry:168h0m0s domain:service.example.com refresh:after 24h0m0s
2016/09/19 17:13:56 http.go:45: HTTP: listening on 0.0.0.0:8080
2016/09/19 17:15:45 oauthproxy.go:535: 10.10.100.127:43619 Cookie "_oauth2_proxy" not present
10.10.100.127 - - [19/Sep/2016:17:15:45 +0000] logs.insight-out.com GET - "/" HTTP/1.1 "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12) AppleWebKit/602.1.50 (KHTML, like Gecko) Version/10.0 Safari/602.1.50" 403 2521 0.059
2016/09/19 17:15:51 oauthproxy.go:478: 10.10.100.127:43619 error redeeming code Post https://www.googleapis.com/oauth2/v3/token: x509: failed to load system roots and no roots provided
2016/09/19 17:15:51 oauthproxy.go:319: ErrorPage 500 Internal Error Internal Error

[itskingori]

Fixed in latest release i.e. 2.1-2.