Reorder dependencies

Cargo.toml

@@ -30,10 +30,10 @@ query_encoding = ["encoding"]
 heap_size = ["heapsize", "heapsize_plugin"]
 
 [dependencies]
-idna = { version = "0.1.0", path = "./idna" }
+encoding = {version = "0.2", optional = true}
 heapsize = {version = ">=0.1.1, <0.4", optional = true}
 heapsize_plugin = {version = "0.1.0", optional = true}
-encoding = {version = "0.2", optional = true}
-serde = {version = ">=0.6.1, <0.8", optional = true}
-rustc-serialize = {version = "0.3", optional = true}
+idna = { version = "0.1.0", path = "./idna" }
 matches = "0.1"
+rustc-serialize = {version = "0.3", optional = true}
+serde = {version = ">=0.6.1, <0.8", optional = true}