chore(deps): Update doc-comment

Author: epage

Cargo.toml

@@ -17,4 +17,4 @@ globwalk = "0.7"
 predicates = "1.0.0"
 predicates-core = "1.0"
 predicates-tree = "1.0"
-doc-comment = "0.1"
+doc-comment = "0.3"

src/lib.rs

@@ -95,6 +95,4 @@ pub mod prelude {
 
 #[macro_use]
 extern crate doc_comment;
-doc_comment! {
-    include_str!("../README.md")
-}
+doctest!("../README.md");