Add expllicit dependencies on base64 and bigdecimal gems.

Author: gkellogg

rdf.gemspec

@@ -31,6 +31,8 @@ Gem::Specification.new do |gem|
   gem.requirements               = []
   gem.add_runtime_dependency     'link_header', '~> 0.0', '>= 0.0.8'
   gem.add_runtime_dependency     'bcp47_spec',  '~> 0.2'
+  gem.add_runtime_dependency     'bigdecimal',  '~> 3.1', '>= 3.1.5'
+  gem.add_development_dependency 'base64',      '~> 0.2'
   gem.add_development_dependency 'rdf-spec',    '~> 3.3'
   gem.add_development_dependency 'rdf-turtle',  '~> 3.3'
   gem.add_development_dependency 'rdf-vocab',   '~> 3.3'