Upgrade DUB dependencies for dpl-docs

Author: wilzbach

dpl-docs/dub.selections.json

@@ -4,11 +4,11 @@
 		"ddox": "0.15.18",
 		"experimental_allocator": "2.70.0-b1",
 		"hyphenate": "1.1.1",
-		"libasync": "0.7.9",
-		"libdparse": "0.7.0-beta.2",
+		"libasync": "0.8.3",
+		"libdparse": "0.7.0",
 		"libev": "5.0.0+4.04",
 		"libevent": "2.0.2+2.0.16",
-		"memutils": "0.4.8",
-		"vibe-d": "0.7.30"
+		"memutils": "0.4.9",
+		"vibe-d": "0.7.31"
 	}
 }