Add token support, resolved #19.

Use CHANGELOG_GITHUB_TOKEN variable to specify token in the shell.

Gemfile

@@ -1,3 +1,4 @@
 source 'https://rubygems.org'
 gem 'github_api'
 gem 'httparty'
+gem 'colorize'

Gemfile.lock

@@ -2,6 +2,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     addressable (2.3.6)
+    colorize (0.7.3)
     descendants_tracker (0.0.4)
       thread_safe (~> 0.3, >= 0.3.1)
     faraday (0.9.0)
@@ -39,5 +40,6 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  colorize
   github_api
   httparty

README.md

@@ -49,7 +49,14 @@ Type `github_changelog_generator --help` for detailed usage.
 
 
 ## FAQ:
-Since GitHub allow to make only 50 requests without authentication it's recommended to run this scrip with key `-t [your-16-digit-token]` that you can easily **[generate it here](https://github.com/settings/applications)**.
+Since GitHub allow to make only 50 requests without authentication it's recommended to run this script with token
+
+**You can easily [generate it here](https://github.com/settings/applications)**.
+
+And:
+
+- Run with key `-t [your-16-digit-token]` that 
+- Or add to your shell variable CHANGELOG_GITHUB_TOKEN and specify there your token
 
 So, if you got error like this:
 >! /Library/Ruby/Gems/2.0.0/gems/github_api-0.12.2/lib/github_api/response/raise_error.rb:14:in `on_complete'

github_changelog_generator.gemspec

@@ -16,6 +16,7 @@ Gem::Specification.new do |s|
   s.license       = "MIT"
   s.add_runtime_dependency(%q<httparty>, ["~> 0.13"])
   s.add_runtime_dependency(%q<github_api>, ["~> 0.12"])
+  s.add_runtime_dependency(%q<colorize>, ["~> 0.7"])
 
   s.executables   = %w(github_changelog_generator)
 end

lib/github_changelog_generator.rb

@@ -3,6 +3,7 @@
 require 'github_api'
 require 'json'
 require 'httparty'
+require 'colorize'
 require_relative 'github_changelog_generator/parser'
 
 
@@ -13,11 +14,15 @@ class ChangelogGenerator
   def initialize()
 
     @options = Parser.parse_options
-    if @options[:token]
-      @github = Github.new oauth_token: @options[:token]
-    else
+
+    github_token
+
+    if @github_token.nil?
       @github = Github.new
+    else
+      @github = Github.new oauth_token: @github_token
     end
+
     @all_tags = self.get_all_tags
     @pull_requests = self.get_all_closed_pull_requests
     @issues = self.get_all_issues
@@ -113,13 +118,13 @@ class ChangelogGenerator
       puts "Receive tags for repo #{url}"
     end
 
-    if @options[:token]
-      response = HTTParty.get(url,
-                              :headers => {'Authorization' => "token #{@options[:token]}",
-                                           'User-Agent' => 'Changelog-Generator'})
-    else
+    if @github_token.nil?
       response = HTTParty.get(url,
                               :headers => {'User-Agent' => 'Changelog-Generator'})
+    else
+      response = HTTParty.get(url,
+                              :headers => {'Authorization' => "token #{@github_token}",
+                                           'User-Agent' => 'Changelog-Generator'})
     end
 
     json_parse = JSON.parse(response.body)
@@ -131,6 +136,23 @@ class ChangelogGenerator
     json_parse
   end
 
+  def github_token
+    if @options[:token]
+      return @github_token ||= @options[:token]
+    end
+
+    env_var = ENV.fetch 'CHANGELOG_GITHUB_TOKEN', nil
+
+    unless env_var
+      puts "Warning: No token provided (-t option) and variable $CHANGELOG_GITHUB_TOKEN was not found.".yellow
+      puts "This script can make only 50 requests to GitHub API per hour without token!".yellow
+    end
+
+    @github_token ||= env_var
+
+  end
+
+
   def generate_log_between_tags(since_tag, till_tag)
     since_tag_time = self.get_time_of_tag(since_tag)
     till_tag_time = self.get_time_of_tag(till_tag)
@@ -325,5 +347,5 @@ end
 
 if __FILE__ == $0
   changelog_generator = ChangelogGenerator.new
-  changelog_generator.compund_changelog
+  # changelog_generator.compund_changelog
 end

lib/github_changelog_generator/parser.rb

@@ -13,7 +13,7 @@ class Parser
       opts.on('-p', '--project [PROJECT]', 'Name of project on GitHub') do |last|
         options[:project] = last
       end
-      opts.on('-t', '--token [TOKEN]', 'To make more than 50 requests this script required your OAuth token for GitHub. You can generate it on https://github.com/settings/applications') do |last|
+      opts.on('-t', '--token [TOKEN]', 'To make more than 50 requests this script required your OAuth token for GitHub. You can generate here: https://github.com/settings/tokens/new') do |last|
         options[:token] = last
       end
       opts.on('-h', '--help', 'Displays Help') do