Fix Build#duration when TimeZone is not UTC

I got wrong Build#durations, cause ServerTime is not UTC.

Sample Output:
    $: build.from
    => Sat, 30 Mar 2013 16:58:42 UTC +00:00

    $: Time.now
     => 2013-03-30 18:20:25 +0100

    $: Time.zone.now
     => Sat, 30 Mar 2013 17:20:29 UTC +00:00
Serving gravatar images form an https source
This is safe to run on gitlab-ci http and https servers
Minor spelling and grammar update to README.md
Merge pull request #192 from drbraden/patch-1

Minor spelling and grammar update to README.md
Adding PostgreSQL to the docs.
Mention GitLab as requirement for CI
Add project_id index to builds
Merge pull request #198 from reuben-sutton/master

Adding a project_id index to builds
Project adding to REST. Restyle application. Left nav for project layout
Added chart. Better tab names for project. Highlight active tab
Fix tests. added icons to project nav
style error pages
Improve UI for GitLab projects page
Improving docs for 3.0
simplecov added
More charts. Correct routes to actual page names
Api rspec
Added changelog and version up to beta
bold notice about 2.2 in readme
Add Runner#assign_to method. Validate runner uniqness in runner_project