Github → GitHub (#7607)

public/app/partials/login.html

@@ -57,7 +57,7 @@
 					</a>
 					<a class="btn btn-large btn-github" href="login/github" target="_self" ng-if="oauth.github">
 						<i class="fa fa-github"></i>
-						with Github
+						with GitHub
 					</a>
 					<a class="btn btn-large btn-grafana-net" href="login/grafananet" target="_self" ng-if="oauth.grafananet">
 						with <span>Grafana.net</span>