[ci] Improve danger message

Dangerfile

@@ -7,20 +7,14 @@ require 'logger'
 def run_pmdtester
   Dir.chdir('..') do
     argv = ['-r', './pmd', '-b', "#{ENV['TRAVIS_BRANCH']}", '-p', 'FETCH_HEAD', '-m', 'online', '-a']
-    Process.fork do
-	  begin
-        runner = PmdTester::Runner.new(argv)
-        introduce_new_pmd_errors = runner.run
-        warn("The PR may introduce new PMD errors!") if introduce_new_pmd_errors
-	  rescue StandardError => e
-	    warn("Running pmdtester failed, this message is mainly used to remind the maintainers of PMD.")
-	    @logger.error "Running pmdtester failed: #{e.inspect}"
-	    exit 1
-	  end
-	end
-	Process.wait
-
-    upload_report if $?.success?
+    begin
+      runner = PmdTester::Runner.new(argv)
+      @new_errors, @removed_errors, @new_violations, @removed_violations = runner.run
+      upload_report
+    rescue StandardError => e
+      warn("Running pmdtester failed, this message is mainly used to remind the maintainers of PMD.")
+      @logger.error "Running pmdtester failed: #{e.inspect}"
+    end
   end
 end
 
@@ -38,7 +32,8 @@ def upload_report
 	  @logger.info "Successfully uploaded #{tar_filename} to chunk.io"
 
       # set value of sticky to true and the message is kept after new commits are submited to the PR
-	  message("Please check the [regression diff report](#{report_url.chomp}/diff/index.html) to make sure that everything is expected", sticky: true)
+	  message("This changeset introduce #{@new_violations} new violations and #{@new_errors} new errors,\n" +
+	          "removes #{@removed_violations} violations and #{@removed_errors} errors. [Full report](#{report_url.chomp}/diff/index.html)", sticky: true)
 	else
       @logger.error "Error while uploading #{tar_filename} to chunk.io: #{report_url}"
       warn("Uploading the diff report failed, this message is mainly used to remind the maintainers of PMD.")

Gemfile

@@ -1,6 +1,6 @@
 source 'https://rubygems.org/'
 
-gem 'pmdtester', '~> 1.0.0.pre.beta3'
+gem 'pmdtester', :git => 'https://github.com/pmd/pmd-regression-tester.git'
 gem 'danger', '~> 5.6', '>= 5.6'
 
 # This group is only needed for rendering release notes