add Troubleshooting section to README

1 job for master
Status Job ID Name Coverage
  Test
failed #9
Build

00:00:11

 
Name Stage Failure
failed
Build Test There is an unknown failure, please try again
npm ERR! System Linux 3.14-1-amd64
npm ERR! command "/usr/local/bin/node" "/usr/local/bin/npm" "stop"
npm ERR! cwd /srv/git/gitlab-ci-runner/tmp/builds/project-1
npm ERR! node -v v0.10.32
npm ERR! npm -v 1.4.28
npm ERR! code ELIFECYCLE
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR! /srv/git/gitlab-ci-runner/tmp/builds/project-1/npm-debug.log
npm ERR! not ok code 0