confirmation modal for deleting an application

- adds delete-confirmation Vue component
- refactors some button styles to make them globally available

styles/elements/_buttons.scss

@@ -11,3 +11,23 @@ button,
     opacity: 0.75;
   }
 }
+
+.button-danger {
+  background: $color-red;
+
+  &:hover {
+    background-color: $color-red-darkest;
+  }
+}
+
+.button-danger-outline, input[type="button"].button-danger-outline {
+  color: $color-red;
+  background-color: $color-red-lightest;
+  box-shadow: inset 0 0 0 1px $color-red;
+
+  &:hover {
+    color: white;
+    background-color: $color-red-darkest;
+    box-shadow: inset 0 0 0 1px $color-red-darkest;
+  }
+}