Use RspecFlaky::Report in scripts/prune-old-flaky-specs

Signed-off-by: Rémy Coutable <remy@rymai.me>

scripts/prune-old-flaky-specs

 #!/usr/bin/env ruby
 
-require 'bundler/setup'
-Bundler.require(:default)
-
-require_relative '../lib/rspec_flaky/flaky_examples_collection'
-require_relative '../lib/rspec_flaky/examples_pruner'
+require_relative '../lib/rspec_flaky/report'
 
 report_file = ARGV.shift
 unless report_file
@@ -13,21 +9,11 @@ unless report_file
 end
 
 new_report_file = ARGV.shift || report_file
-
-DAYS_THRESHOLD = 90
-
-def days_from_now(days)
-  Time.now - (3600 * 24 * days)
-end
-
+report = RspecFlaky::Report.load(report_file)
 puts "Loading #{report_file}..."
-collection = RspecFlaky::FlakyExamplesCollection.new(JSON.parse(File.read(report_file)))
-
-puts "Current report has #{collection.size} entries."
-
-new_collection = RspecFlaky::ExamplesPruner.new(collection).prune_examples_older_than(days_from_now(DAYS_THRESHOLD))
+puts "Current report has #{report.size} entries."
 
-puts "New report has #{new_collection.size} entries: #{collection.size - new_collection.size} entries older than #{DAYS_THRESHOLD} days were removed."
+new_report = report.prune_outdated
 
-File.write(new_report_file, JSON.pretty_generate(new_collection.to_report))
-puts "Saved #{new_report_file}."
+puts "New report has #{new_report.size} entries: #{report.size - new_report.size} entries older than 90 days were removed."
+puts "Saved #{new_report_file}." if new_report.write(new_report_file)