Update dbl -> topgg and bump version to 1.2.0

Author: Chew

dblruby.gemspec

@@ -1,9 +1,9 @@
 Gem::Specification.new do |s|
   s.name = 'dblruby'
-  s.version = '1.1.3'
-  s.date = '2019-04-22'
-  s.summary = 'Discord Bot List API for Ruby'
-  s.description = 'A Ruby library for the Discord Bot List (https://discordbots.org) API.'
+  s.version = '1.2.0'
+  s.date = '2020-06-19'
+  s.summary = 'Top.gg / Discord Bot List API for Ruby'
+  s.description = 'A Ruby library for the Top.gg (https://top.gg) API.'
   s.authors = ['Chew']
   s.email = '[email protected]'
   s.files = Dir['lib/**/*.rb']