Removed Warnings

Author: jinosh05

example/lib/main.dart

@@ -17,7 +17,7 @@ class FontAwesomeGalleryApp extends StatelessWidget {
       theme: ThemeData.light().copyWith(
         iconTheme: const IconThemeData(size: 36.0, color: Colors.black87),
         textTheme: const TextTheme(
-          bodyText2: TextStyle(fontSize: 16.0, color: Colors.black87),
+          bodyMedium: TextStyle(fontSize: 16.0, color: Colors.black87),
         ),
       ),
       home: const FontAwesomeGalleryHome(),

util/lib/main.dart

@@ -103,8 +103,7 @@ void main(List<String> rawArgs) async {
     const repositoryName = 'FortAwesome/Font-Awesome';
     final defaultBranch = await getRepositoryDefaultBranch(repositoryName);
     print(blue(
-        'Choosing branch "$defaultBranch" of repository https://github.com/' +
-            repositoryName));
+        'Choosing branch "$defaultBranch" of repository https://github.com/$repositoryName'));
     await download(
         'https://raw.githubusercontent.com/FortAwesome/Font-Awesome/$defaultBranch/metadata/icons.json',
         File('lib/fonts/icons.json'));
@@ -228,7 +227,7 @@ void adjustPubspecFontIncludes(Set<String> styles) {
 /// Comments out a line of yaml code. Does nothing if already commented
 String commentYamlLine(String line) {
   if (line.startsWith('#')) return line;
-  return '#' + line;
+  return '#$line';
 }
 
 /// Uncomments a line of yaml code. Does nothing if not commented.
@@ -455,7 +454,7 @@ String styleToDataSource(String style) {
 /// using the latest version, this tool always selects the default branch.
 Future<String> getRepositoryDefaultBranch(String repositoryName) async {
   final tmpFile = File('fa-repo-metadata.tmp');
-  await download('https://api.github.com/repos/' + repositoryName, tmpFile);
+  await download('https://api.github.com/repos/$repositoryName', tmpFile);
   try {
     String rawGithubMetadata = await tmpFile.readAsString();
     Map<String, dynamic> githubMetadata = json.decode(rawGithubMetadata);
@@ -476,12 +475,10 @@ Future printVersionNotice(String repositoryName) async {
   try {
     final packageVersion = pub.Version.parse(getPackageVersion());
 
-    print(blue(
-        'Using font_awesome_flutter version ' + packageVersion.toString()));
+    print(blue('Using font_awesome_flutter version $packageVersion'));
 
     await download(
-        'https://api.github.com/repos/' + repositoryName + '/releases',
-        tmpFile);
+        'https://api.github.com/repos/$repositoryName/releases', tmpFile);
 
     String rawReleasesData = await tmpFile.readAsString();
     List releasesData = json.decode(rawReleasesData);
@@ -509,17 +506,13 @@ Future printVersionNotice(String repositoryName) async {
     final primaryPreRelease = pub.Version.primary(preReleases);
 
     if (primaryRelease > packageVersion) {
-      print(red('A new version (' +
-          primaryRelease.toString() +
-          ') of font_awesome_flutter is available. Please update before reporting any errors. You can update via `git pull` or by downloading the source code from github. (https://github.com/' +
-          repositoryName +
-          ')'));
+      print(red(
+          'A new version ($primaryRelease) of font_awesome_flutter is available. Please update before reporting any errors. You can update via `git pull` or by downloading the source code from github. (https://github.com/$repositoryName)'));
     }
     if (primaryPreRelease > packageVersion &&
         primaryPreRelease > primaryRelease) {
-      print(yellow('A pre-release version (' +
-          primaryPreRelease.toString() +
-          ') of font_awesome_flutter is available. Should you encounter any problems, have a look if it fixes them.'));
+      print(yellow(
+          'A pre-release version ($primaryPreRelease) of font_awesome_flutter is available. Should you encounter any problems, have a look if it fixes them.'));
     }
   } on FormatException catch (_) {
     print(red(