Added .admonition to the CSS (#462)

Now generic admonitions are styled too.

Author: evildmp

sass/_theme_rst.sass

@@ -50,7 +50,7 @@
   .literal-block, pre.literal-block
     @extend .codeblock
   // These are the various note pullouts that sphinx applies
-  .note, .attention, .caution, .danger, .error, .hint, .important, .tip, .warning, .seealso, .admonition-todo
+  .note, .attention, .caution, .danger, .error, .hint, .important, .tip, .warning, .seealso, .admonition-todo, .admonition
     @extend .wy-alert
     .last
       margin-bottom: 0
@@ -119,7 +119,7 @@
         display: inline-block
     &:hover .headerlink
       display: inline-block
-  
+
   .centered
     text-align: center