Prepare for dartdoc 0.20.4 (#1750)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d6713b..3ed199d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+## 0.20.4
+* Hide pragma declarations from generated docs (#1726)
+* Fix problems with lists in markdown not being handled correctly (#172)
+* Properly escape types inside comment references (#1740)
+* Generate a custom page, `__404error.html`, for use as an error page (#1704)
+* Generate an error on unresolved exports instead of crashing (#1745)
+* Generate anchors for headers in markdown (#1749)
+
 ## 0.20.3
 * Update dependencies and fork mustache4dart into dartdoc so dartdoc can resolve
   dependencies on Dart 2.0 stable.
diff --git a/lib/dartdoc.dart b/lib/dartdoc.dart
index 2b9d476..f3a1e24 100644
--- a/lib/dartdoc.dart
+++ b/lib/dartdoc.dart
@@ -37,7 +37,7 @@
 
 const String name = 'dartdoc';
 // Update when pubspec version changes.
-const String dartdocVersion = '0.20.3';
+const String dartdocVersion = '0.20.4';
 
 /// Helper class to initialize the default generators since they require
 /// GeneratorContext.
diff --git a/pubspec.yaml b/pubspec.yaml
index 142a4df..f1c2a45 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: dartdoc
 # Also update the `version` field in lib/dartdoc.dart.
-version: 0.20.3
+version: 0.20.4
 author: Dart Team <misc@dartlang.org>
 description: A documentation generator for Dart.
 homepage: https://github.com/dart-lang/dartdoc
diff --git a/testing/test_package_docs/__404error.html b/testing/test_package_docs/__404error.html
index de2d8e2..f536a6b 100644
--- a/testing/test_package_docs/__404error.html
+++ b/testing/test_package_docs/__404error.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="generator" content="made with love by dartdoc 0.20.3">
+  <meta name="generator" content="made with love by dartdoc 0.20.4">
   <meta name="description" content="test_package API docs, for the Dart programming language.">
   <title>test_package - Dart API docs</title>
 
diff --git a/testing/test_package_docs/index.html b/testing/test_package_docs/index.html
index a2ee4d3..4265511 100644
--- a/testing/test_package_docs/index.html
+++ b/testing/test_package_docs/index.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="generator" content="made with love by dartdoc 0.20.3">
+  <meta name="generator" content="made with love by dartdoc 0.20.4">
   <meta name="description" content="test_package API docs, for the Dart programming language.">
   <title>test_package - Dart API docs</title>
 
diff --git a/testing/test_package_docs_dev/__404error.html b/testing/test_package_docs_dev/__404error.html
index de2d8e2..f536a6b 100644
--- a/testing/test_package_docs_dev/__404error.html
+++ b/testing/test_package_docs_dev/__404error.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="generator" content="made with love by dartdoc 0.20.3">
+  <meta name="generator" content="made with love by dartdoc 0.20.4">
   <meta name="description" content="test_package API docs, for the Dart programming language.">
   <title>test_package - Dart API docs</title>
 
diff --git a/testing/test_package_docs_dev/index.html b/testing/test_package_docs_dev/index.html
index a2ee4d3..4265511 100644
--- a/testing/test_package_docs_dev/index.html
+++ b/testing/test_package_docs_dev/index.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="generator" content="made with love by dartdoc 0.20.3">
+  <meta name="generator" content="made with love by dartdoc 0.20.4">
   <meta name="description" content="test_package API docs, for the Dart programming language.">
   <title>test_package - Dart API docs</title>