Add .bs-callout styles

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/gl_bootstrap.scss

@@ -127,3 +127,48 @@
     padding: 6px 9px;
   }
 }
+
+/*
+ * Callouts from Bootstrap3 docs
+ *
+ * Not quite alerts, but custom and helpful notes for folks reading the docs.
+ * Requires a base and modifier class.
+ */
+
+/* Common styles for all types */
+.bs-callout {
+  margin: 20px 0;
+  padding: 20px;
+  border-left: 3px solid #eee;
+  color: #666;
+  background: #f9f9f9;
+}
+.bs-callout h4 {
+  margin-top: 0;
+  margin-bottom: 5px;
+}
+.bs-callout p:last-child {
+  margin-bottom: 0;
+}
+
+/* Variations */
+.bs-callout-danger {
+  background-color: #fdf7f7;
+  border-color: #eed3d7;
+  color: #b94a48;
+}
+.bs-callout-warning {
+  background-color: #faf8f0;
+  border-color: #faebcc;
+  color: #8a6d3b;
+}
+.bs-callout-info {
+  background-color: #f4f8fa;
+  border-color: #bce8f1;
+  color: #34789a;
+}
+.bs-callout-success {
+  background-color: #dff0d8;
+  border-color: #5cA64d;
+  color: #3c763d;
+}