Add --max-issues argument to limit requests

This addresses issue 71 by providing a configurable limit on the number of issues to retrieve. By default this limits the number of issues to 500 which should help users stay under the GitHub API limit and keep change logs from growing ridiculous in size for older repos.

README.md

@@ -96,6 +96,7 @@ Type `github_changelog_generator --help` for detailed usage.
         --[no-]compare-link          Include compare link between older version and newer version. Default is true
         --include-labels  x,y,z      Issues only with that labels will be included to changelog. Default is 'bug,enhancement'
         --exclude-labels  x,y,z      Issues with that labels will be always excluded from changelog. Default is 'duplicate,question,invalid,wontfix'
+        --max-issues [NUMBER]        Max number of issues to fetch from GitHub. Default is 500.
         --github-site [URL]          The Enterprise Github site on which your project is hosted.
         --github-api [URL]           The enterprise endpoint to use for your Github API.
     -v, --version                    Print version number

lib/github_changelog_generator.rb

@@ -596,6 +596,7 @@ begin
            page_i += PER_PAGE_NUMBER
            print "Fetching issues... #{page_i}/#{count_pages * PER_PAGE_NUMBER}\r"
            issues.concat(page)
+           break if issues.length >= @options[:max_issues]
          end
 rescue
          puts "Warning: GitHub API rate limit exceed (5000 per hour), change log may not contain some issues.".yellow

lib/github_changelog_generator/parser.rb

@@ -24,6 +24,7 @@ module GitHubChangelogGenerator
           :enhancement_prefix => '**Implemented enhancements:**',
           :author => true,
           :filter_issues_by_milestone => true,
+          :max_issues => 500,
           :compare_link => true,
           :unreleased => true,
           :unreleased_label => 'Unreleased',
@@ -83,6 +84,9 @@ module GitHubChangelogGenerator
         opts.on('--exclude-labels  x,y,z', Array, 'Issues with that labels will be always excluded from changelog. Default is \'duplicate,question,invalid,wontfix\'') do |list|
           options[:exclude_labels] = list
         end
+        opts.on('--max-issues [NUMBER]', Integer, 'Max number of issues to fetch from GitHub. Default is 500') do |max|
+          options[:max_issues] = max
+        end
         opts.on('--github-site [URL]', 'The Enterprise Github site on which your project is hosted.') do |last|
           options[:github_site] = last
         end