Fix copy-to-clipboard button CSS

In a lot of browsers, the static position is 0px
anyway so there's no problem.

In IE11, the button sits to the left of the
paragraph above by default. Setting it in the CSS
fixes the issue.

app/assets/stylesheets/components/api-key.scss

@@ -22,6 +22,7 @@
 
     position: absolute;
     bottom: 2px;
+    left: 0px;
 
     &:active {
       top: auto;