diff --git a/.gitignore b/.gitignore
index a3095ab3..39f54dc3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@ spec/reports
 test/tmp
 test/version_tmp
 tmp
+vendor/cache
 
 Gemfile.lock
 out/
diff --git a/.rubocop.yml b/.rubocop.yml
index 40b099bf..abdc5b48 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -6,9 +6,6 @@ Style/StringLiterals:
   Enabled: true
   EnforcedStyle: single_quotes
 
-RequireParentheses:
-  Enabled: true
-
 Naming/FileName:
   Enabled: false
 
diff --git a/.travis.yml b/.travis.yml
index 8e415bf9..03afed4d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,8 @@ rvm:
   - 2.4.3
   - 2.5.0
   - 2.6.0
+  - 2.7.0
+  - ruby-head
 
 git:
   depth: 10
@@ -16,6 +18,8 @@ sudo: false
 cache: bundler
 
 matrix:
+  allow_failures:
+    - rvm: ruby-head
   include:
     - script: bundle exec rake rubocop
-      rvm: 2.6.0
+      rvm: 2.7.0
diff --git a/lib/html-proofer.rb b/lib/html-proofer.rb
index 1900fa15..d828b453 100644
--- a/lib/html-proofer.rb
+++ b/lib/html-proofer.rb
@@ -2,7 +2,7 @@
 
 def require_all(path)
   dir = File.join(File.dirname(__FILE__), path)
-  Dir[File.join(dir, '*.rb')].each do |f|
+  Dir[File.join(dir, '*.rb')].sort.each do |f|
     require f
   end
 end
diff --git a/lib/html-proofer/log.rb b/lib/html-proofer/log.rb
index 27177ce0..01d4fbb9 100644
--- a/lib/html-proofer/log.rb
+++ b/lib/html-proofer/log.rb
@@ -7,16 +7,27 @@ module HTMLProofer
   class Log
     include Yell::Loggable
 
+    STDOUT_LEVELS = %i[debug info warn].freeze
+    STDERR_LEVELS = %i[error fatal].freeze
+
     def initialize(log_level)
       @logger = Yell.new(format: false, \
                          name: 'HTMLProofer', \
                          level: "gte.#{log_level}") do |l|
-        l.adapter :stdout, level: %i[debug info warn]
-        l.adapter :stderr, level: %i[error fatal]
+        l.adapter :stdout, level: 'lte.warn'
+        l.adapter :stderr, level: 'gte.error'
       end
     end
 
     def log(level, message)
+      log_with_color(level, message)
+    end
+
+    def log_with_color(level, message)
+      @logger.send level, colorize(level, message)
+    end
+
+    def colorize(level, message)
       color = case level
               when :debug
                 :cyan
@@ -28,15 +39,8 @@ def log(level, message)
                 :red
               end
 
-      log_with_color(level, color, message)
-    end
-
-    def log_with_color(level, color, message)
-      @logger.send level, colorize(color, message)
-    end
-
-    def colorize(color, message)
-      if $stdout.isatty && $stderr.isatty
+      if (STDOUT_LEVELS.include?(level) && $stdout.isatty) || \
+         (STDERR_LEVELS.include?(level) && $stderr.isatty)
         Rainbow(message).send(color)
       else
         message
diff --git a/lib/html-proofer/runner.rb b/lib/html-proofer/runner.rb
index e10568f1..1d7f2b9d 100644
--- a/lib/html-proofer/runner.rb
+++ b/lib/html-proofer/runner.rb
@@ -45,7 +45,7 @@ def run
       end
 
       if @failures.empty?
-        @logger.log_with_color :info, :green, 'HTML-Proofer finished successfully.'
+        @logger.log :info, 'HTML-Proofer finished successfully.'
       else
         print_failed_tests
       end
@@ -169,7 +169,7 @@ def print_failed_tests
       sorted_failures.sort_and_report
       count = @failures.length
       failure_text = pluralize(count, 'failure', 'failures')
-      raise @logger.colorize :red, "HTML-Proofer found #{failure_text}!"
+      raise @logger.colorize :fatal, "HTML-Proofer found #{failure_text}!"
     end
   end
 end