use pmdtester 1.0.0.pre.beta3

Dangerfile

@@ -1,4 +1,4 @@
-require 'pmdtester/runner'
+require 'pmdtester'
 require 'time'
 require 'logger'
 
@@ -6,14 +6,15 @@ require 'logger'
 
 def run_pmdtester
   Dir.chdir('..') do
-    argv = ['-r', './pmd', '-b', "#{ENV['TRAVIS_BRANCH']}", '-p', 'FETCH_HEAD', '-m', 'online']
+    argv = ['-r', './pmd', '-b', "#{ENV['TRAVIS_BRANCH']}", '-p', 'FETCH_HEAD', '-m', 'online', '-a']
     Process.fork do
 	  begin
         runner = PmdTester::Runner.new(argv)
-        runner.run # Optimize: get more information from runner, e.g. introduce new pmd errors?
+        introduce_new_pmd_errors = runner.run
+        warn("The PR may introduce new PMD errors!") if introduce_new_pmd_errors
 	  rescue StandardError => e
-	    @logger.error "Running pmdtester failed: #{e.msg}"
 	    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
@@ -37,7 +38,6 @@ 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)
 	else
       @logger.error "Error while uploading #{tar_filename} to chunk.io: #{report_url}"