The bundled Test::Base is outdated and causes warnings.

While at it, remove other bundled modules as well (except
Module::Install::*); we build depend on the separate packages instead.

--- libconvert-pem-perl.orig/Makefile.PL
+++ libconvert-pem-perl/Makefile.PL
@@ -11,8 +11,8 @@
 
 test_requires 'Test::More';
 test_requires 'Test::Exception';
+test_requires 'Test::Base';
 
-use_test_base;
 auto_include_deps;
 author_tests('xt');
 auto_set_repository;
--- libconvert-pem-perl.orig/MANIFEST
+++ libconvert-pem-perl/MANIFEST
@@ -12,14 +12,6 @@
 inc/Module/Install/TestBase.pm
 inc/Module/Install/Win32.pm
 inc/Module/Install/WriteAll.pm
-inc/Spiffy.pm
-inc/Sub/Uplevel.pm
-inc/Test/Base.pm
-inc/Test/Base/Filter.pm
-inc/Test/Builder.pm
-inc/Test/Builder/Module.pm
-inc/Test/Exception.pm
-inc/Test/More.pm
 lib/Convert/PEM.pm
 lib/Convert/PEM/CBC.pm
 Makefile.PL
