Get rid of all the library tags.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1580653005 .
diff --git a/lib/src/eager_span_scanner.dart b/lib/src/eager_span_scanner.dart
index 3fae5cc..c537b0c 100644
--- a/lib/src/eager_span_scanner.dart
+++ b/lib/src/eager_span_scanner.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.eager_span_scanner;
-
 import 'package:charcode/ascii.dart';
 
 import 'line_scanner.dart';
diff --git a/lib/src/exception.dart b/lib/src/exception.dart
index 50177d6..84bf5e8 100644
--- a/lib/src/exception.dart
+++ b/lib/src/exception.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.exception;
-
 import 'package:source_span/source_span.dart';
 
 /// An exception thrown by a [StringScanner] that failed to parse a string.
diff --git a/lib/src/line_scanner.dart b/lib/src/line_scanner.dart
index 66d7575..b439193 100644
--- a/lib/src/line_scanner.dart
+++ b/lib/src/line_scanner.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.line_scanner;
-
 import 'package:charcode/ascii.dart';
 
 import 'string_scanner.dart';
diff --git a/lib/src/span_scanner.dart b/lib/src/span_scanner.dart
index ebe230d..dd16e47 100644
--- a/lib/src/span_scanner.dart
+++ b/lib/src/span_scanner.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.span_scanner;
-
 import 'package:source_span/source_span.dart';
 
 import 'eager_span_scanner.dart';
diff --git a/lib/src/string_scanner.dart b/lib/src/string_scanner.dart
index d9c1c2f..775dd5e 100644
--- a/lib/src/string_scanner.dart
+++ b/lib/src/string_scanner.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.string_scanner;
-
 import 'package:source_span/source_span.dart';
 
 import 'exception.dart';
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index 107c4c5..aa3e957 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.utils;
-
 /// Validates the arguments passed to [StringScanner.error].
 void validateErrorArgs(String string, Match match, int position, int length) {
   if (match != null && (position != null || length != null)) {
diff --git a/lib/string_scanner.dart b/lib/string_scanner.dart
index be294f4..7f36eef 100644
--- a/lib/string_scanner.dart
+++ b/lib/string_scanner.dart
@@ -3,8 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /// A library for parsing strings using a sequence of patterns.
-library string_scanner;
-
 export 'src/exception.dart';
 export 'src/line_scanner.dart';
 export 'src/span_scanner.dart';
diff --git a/test/error_test.dart b/test/error_test.dart
index 9c485e5..ff45194 100644
--- a/test/error_test.dart
+++ b/test/error_test.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.error_test;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
diff --git a/test/line_scanner_test.dart b/test/line_scanner_test.dart
index 68e5c38..9874cb3 100644
--- a/test/line_scanner_test.dart
+++ b/test/line_scanner_test.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.line_scanner_test;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
diff --git a/test/span_scanner_test.dart b/test/span_scanner_test.dart
index 114bff7..b078f6e 100644
--- a/test/span_scanner_test.dart
+++ b/test/span_scanner_test.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.span_scanner_test;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
diff --git a/test/string_scanner_test.dart b/test/string_scanner_test.dart
index c8e43a5..10e622a 100644
--- a/test/string_scanner_test.dart
+++ b/test/string_scanner_test.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.string_scanner_test;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
diff --git a/test/utils.dart b/test/utils.dart
index 8df4b51..471b4c8 100644
--- a/test/utils.dart
+++ b/test/utils.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library string_scanner.test.utils;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';