Relax base64 dependency version

Version 0.2.0 of base64 has no functional differences with previous versions and
some gems still require a previous version of base64.

Author: chileung-b4b

rb/Gemfile.lock

@@ -4,7 +4,7 @@ PATH
     selenium-devtools (0.129.0)
       selenium-webdriver (~> 4.2)
     selenium-webdriver (4.26.0.nightly)
-      base64 (~> 0.2)
+      base64 (>= 0.1.1, < 0.3)
       logger (~> 1.4)
       rexml (~> 3.2, >= 3.2.5)
       rubyzip (>= 1.2.2, < 3.0)

rb/selenium-webdriver.gemspec

@@ -47,7 +47,7 @@ Gem::Specification.new do |s|
   s.bindir = 'bin'
   s.require_paths = ['lib']
 
-  s.add_dependency 'base64', ['~> 0.2']
+  s.add_dependency 'base64', ['>= 0.1.1', '< 0.3']
   s.add_dependency 'logger', ['~> 1.4']
   s.add_dependency 'rexml', ['~> 3.2', '>= 3.2.5']
   s.add_dependency 'rubyzip', ['>= 1.2.2', '< 3.0']