Get rid of all the library tags.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1581853003 .
diff --git a/lib/pub_semver.dart b/lib/pub_semver.dart
index 436e226..fd2320e 100644
--- a/lib/pub_semver.dart
+++ b/lib/pub_semver.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 pub_semver;
-
 export 'src/version.dart';
 export 'src/version_constraint.dart';
 export 'src/version_range.dart';
diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index 8b32900..4e57ec9 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.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 pub_semver.src.patterns;
-
 /// Regex that matches a version number at the beginning of a string.
 final START_VERSION = new RegExp(
     r'^'                                        // Start at beginning.
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index 2853e5c..74d015a 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 pub_semver.src.utils;
-
 import 'version_range.dart';
 
 /// Returns whether [range1] is immediately next to, but not overlapping,
diff --git a/lib/src/version.dart b/lib/src/version.dart
index 51972f7..528c3a2 100644
--- a/lib/src/version.dart
+++ b/lib/src/version.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 pub_semver.src.version;
-
 import 'dart:math' as math;
 
 import 'package:collection/equality.dart';
diff --git a/lib/src/version_constraint.dart b/lib/src/version_constraint.dart
index f84d882..f222b51 100644
--- a/lib/src/version_constraint.dart
+++ b/lib/src/version_constraint.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 pub_semver.src.version_constraint;
-
 import 'patterns.dart';
 import 'version.dart';
 import 'version_range.dart';
diff --git a/lib/src/version_range.dart b/lib/src/version_range.dart
index 5c53834..668b9b2 100644
--- a/lib/src/version_range.dart
+++ b/lib/src/version_range.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 pub_semver.src.version_range;
-
 import 'version.dart';
 import 'version_constraint.dart';
 import 'version_union.dart';
diff --git a/lib/src/version_union.dart b/lib/src/version_union.dart
index a671514..2799341 100644
--- a/lib/src/version_union.dart
+++ b/lib/src/version_union.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 pub_semver.src.version_union;
-
 import 'package:collection/collection.dart';
 
 import 'utils.dart';
diff --git a/test/utils.dart b/test/utils.dart
index 6fefdae..e1d7446 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 pub_semver.test.utils;
-
 import 'package:test/test.dart';
 
 import 'package:pub_semver/pub_semver.dart';
diff --git a/test/version_constraint_test.dart b/test/version_constraint_test.dart
index b383054..bd6bf75 100644
--- a/test/version_constraint_test.dart
+++ b/test/version_constraint_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 pub_semver.test.version_constraint_test;
-
 import 'package:test/test.dart';
 
 import 'package:pub_semver/pub_semver.dart';
diff --git a/test/version_range_test.dart b/test/version_range_test.dart
index 6df6b31..9eaa980 100644
--- a/test/version_range_test.dart
+++ b/test/version_range_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 pub_semver.test.version_range_test;
-
 import 'package:test/test.dart';
 
 import 'package:pub_semver/pub_semver.dart';
diff --git a/test/version_test.dart b/test/version_test.dart
index e3d1b49..ddc6c94 100644
--- a/test/version_test.dart
+++ b/test/version_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 pub_semver.test.version_test;
-
 import 'package:test/test.dart';
 
 import 'package:pub_semver/pub_semver.dart';