Add formatting libraries to composer.json

vendor/leafo/lessphp/tests/outputs/mixin_merging.css

@@ -0,0 +1,42 @@
+#test1 div {
+  color:red;
+  height:10px;
+}
+#test1 p { height:10px; }
+#test2 b {
+  color:red;
+  width:1px;
+}
+#test2 a, #test2 i { width:1px; }
+#test3 a, #test3 i { width:1px; }
+#test3 b {
+  width:1px;
+  color:red;
+}
+#test4 a {
+  color:blue;
+  margin:1px;
+}
+#test4 div, #test4 html { color:blue; }
+#test5 img, #test5 strong {
+  padding:2px;
+  float:right;
+}
+#test6 div a, #test6 span a {
+  line-height:10px;
+  color:red;
+}
+#test7 div strong {
+  margin:1px;
+  color:red;
+}
+#test7 div b { color:red; }
+#test7 span strong, #test7 span b { color:red; }
+#test8 a i, #test8 b i {
+  background:red;
+  color:red;
+}
+#test8 a s, #test8 b s {
+  background:red;
+  color:blue;
+}