Made buttons keyboard accessible.

src/styles/_components.scss

@@ -53,6 +53,7 @@
   font-size: $font-size-6;
   padding: $margin-2;
   user-select: none;
+  border-width: 0;
   border-radius: 2px;
   box-sizing: border-box;
 

src/styles/_input.scss

@@ -91,7 +91,6 @@
 
 .maputnik-button-selected {
   background-color: lighten($color-midgray, 12);
-  outline: 1px $color-white;
   color: white;
 }
 

src/styles/_toolbar.scss

@@ -57,6 +57,8 @@
 }
 
 .maputnik-toolbar-action {
+  background: inherit;
+  border-width: 0;
   @extend .maputnik-toolbar-link;
 }