Disable Gravatar (#37)

* Disable Gravatar
* Lowercase emails
* Add migration

templates/pages/revisions.html

@@ -10,8 +10,9 @@
                 <svg xmlns="http://www.w3.org/2000/svg" class="h-3 w-3 mr-1 inline" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="2">
                     <path stroke-linecap="round" stroke-linejoin="round" d="M13 5l7 7-7 7M5 5l7 7-7 7" />
                 </svg>
-                <img class="h-5 w-5 rounded-full inline" src="{{ avatarUrl (emailToMD5 $commit.AuthorEmail) }}" alt="" />
-                <span class="font-bold">{{ $commit.AuthorName }}</span> revised this gist <span class="moment-timestamp font-bold">{{ $commit.Timestamp }}</span>. <a href="/{{ $.gist.User.Username }}/{{ $.gist.Uuid }}/rev/{{ $commit.Hash }}">Go to revision</a></h3>
+                {{ $user := (index $.emails $commit.AuthorEmail) }}
+                <img class="h-5 w-5 rounded-full inline" src="{{if $user }}{{ avatarUrl $user $.DisableGravatar }}{{else}}{{defaultAvatar}}{{end}}" alt="" />
+                <span class="font-bold">{{if $user}}<a href="/{{$user.Username}}" class="text-slate-300 hover:text-slate-300 hover:underline">{{ $commit.AuthorName }}</a>{{else}}{{ $commit.AuthorName }}{{end}}</span> revised this gist <span class="moment-timestamp font-bold">{{ $commit.Timestamp }}</span>. <a href="/{{ $.gist.User.Username }}/{{ $.gist.Uuid }}/rev/{{ $commit.Hash }}">Go to revision</a></h3>
                 {{ if ne $commit.Changed "" }}
                     <p class="text-sm float-right py-2">
                     <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" class="w-5 h-5 inline-flex">