Run webpacker:info in Rails.root

This is resolution to problems that occur with a mounted Rails engine.
With one of these you would want to run `rake app:webpacker:info` and
have it run against the Rails app you'd be mounting in (normally in
test/dummy) however it would incorrectly run in the root directory -
where you probably don't want to have webpacker and webpacker-dev-server
installed.

lib/tasks/webpacker/info.rake

@@ -3,17 +3,19 @@ require "webpacker/version"
 namespace :webpacker do
   desc "Provide information on Webpacker's environment"
   task :info do
-    $stdout.puts "Ruby: #{`ruby --version`}"
-    $stdout.puts "Rails: #{Rails.version}"
-    $stdout.puts "Webpacker: #{Webpacker::VERSION}"
-    $stdout.puts "Node: #{`node --version`}"
-    $stdout.puts "Yarn: #{`yarn --version`}"
+    Dir.chdir(Rails.root) do
+      $stdout.puts "Ruby: #{`ruby --version`}"
+      $stdout.puts "Rails: #{Rails.version}"
+      $stdout.puts "Webpacker: #{Webpacker::VERSION}"
+      $stdout.puts "Node: #{`node --version`}"
+      $stdout.puts "Yarn: #{`yarn --version`}"
 
-    $stdout.puts "\n"
-    $stdout.puts "@rails/webpacker: \n#{`npm list @rails/webpacker version`}"
+      $stdout.puts "\n"
+      $stdout.puts "@rails/webpacker: \n#{`npm list @rails/webpacker version`}"
 
-    $stdout.puts "Is bin/webpack present?: #{File.exist? 'bin/webpack'}"
-    $stdout.puts "Is bin/webpack-dev-server present?: #{File.exist? 'bin/webpack-dev-server'}"
-    $stdout.puts "Is bin/yarn present?: #{File.exist? 'bin/yarn'}"
+      $stdout.puts "Is bin/webpack present?: #{File.exist? 'bin/webpack'}"
+      $stdout.puts "Is bin/webpack-dev-server present?: #{File.exist? 'bin/webpack-dev-server'}"
+      $stdout.puts "Is bin/yarn present?: #{File.exist? 'bin/yarn'}"
+    end
   end
 end