Configure OSEM via environment variables

Instead of reading a yaml file we get configuration from the
environment.

app/views/layouts/schedule.html.haml

@@ -3,7 +3,7 @@
   %head
     %meta{:charset => "utf-8"}
     %meta{:name => "viewport", :content => "width=device-width, initial-scale=1, maximum-scale=1"}
-    %title= content_for?(:title) ? yield(:title) : CONFIG['name']
+    %title= content_for?(:title) ? yield(:title) : (ENV['OSEM_NAME'] || 'OSEM')
     %meta{:content => "", :name => "description"}
     %meta{:content => "", :name => "author"}
     = stylesheet_link_tag "/stylesheets/schedule/jquery-ui-1.9.2.custom.min"
@@ -17,4 +17,4 @@
     = yield(:head)
   %body
     .content
-      = yield
+      = yield