clean up usage css

geomagio/webservice/static/usage.css

-.space-between {
-  margin: 1em 0 0;
-}
-
-.space-between > a {
-  color: #fff;
-  display: inline-block;
-  margin: 0.5em 1em 0.5em 0;
-}
-
-.space-between > a:active {
-  color: #fff;
-}
-
-.space-between {
-  border-top: 1px solid #eee;
-}
-@media screen and (min-width: 1000px) {
-  .space-between {
-    display: flex;
-    justify-content: space-between;
-  }
-}