Custom badges

[pflannery]

Would be nice to be able to add custom badges like:

badges: 
  custom:
    analytics:
      text: 'Analytics'
      image: 'https://ga-beacon.appspot.com/some-ga-code/some-repo/readme'
      url: 'https://github.com/some-org-auth/some-repo'
      tooltip: 'hello'

something like the following code put into misc badges to parse these custom badges

custom = (opts) ->
  if opts == null
    opts = {}
  if !opts.badges.custom or !opts.name
    return ''
  else
    results = ''
    for key of opts.badges.custom
      customInfo = opts.badges.custom[key]
      tooltipFmtd = if customInfo.tooltip then ' "' + customInfo.tooltip + '"' else ''
      results += '[![' + customInfo.text + '](' + customInfo.image + ')](' + customInfo.url + tooltipFmtd + ')'

  results

I'll be happy to pull on this

[balupton]

v1.0.0 resolves this