Update gemspec

Author: adangel

pmdtester.gemspec

@@ -11,7 +11,7 @@ Gem::Specification.new do |s|
   s.metadata = { "bug_tracker_uri" => "https://github.com/pmd/pmd-regression-tester/issues", "homepage_uri" => "https://pmd.github.io", "source_code_uri" => "https://github.com/pmd/pmd-regression-tester" } if s.respond_to? :metadata=
   s.require_paths = ["lib".freeze]
   s.authors = ["Andreas Dangel".freeze, "Binguo Bao".freeze, "Cl\u00E9ment Fournier".freeze]
-  s.date = "2020-12-03"
+  s.date = "2020-12-05"
   s.description = "A regression testing tool ensure that new problems and unexpected behaviors will not be introduced to PMD project after fixing an issue , and new rules can work as expected.".freeze
   s.email = ["[email protected]".freeze, "[email protected]".freeze, "[email protected]".freeze]
   s.executables = ["pmdtester".freeze]