Require redis before 4, which introduces a breaking change.

Gemfile.lock

@@ -3,7 +3,7 @@ PATH
   specs:
     qless (0.10.3)
       metriks (~> 0.9)
-      redis (>= 2.2)
+      redis (>= 2.2, < 4)
       rusage (~> 0.2.0)
       sentry-raven (~> 0.4)
       sinatra (~> 1.3)
@@ -47,12 +47,12 @@ GEM
     debugger-ruby_core_source (1.2.3)
     diff-lcs (1.2.4)
     eventmachine (1.0.9.1)
-    faraday (0.9.2)
+    faraday (0.10.0)
       multipart-post (>= 1.2, < 3)
     faye-websocket (0.4.7)
       eventmachine (>= 0.12.0)
     ffi (1.9.0)
-    hitimes (1.2.3)
+    hitimes (1.2.4)
     http_parser.rb (0.5.3)
     method_source (0.8.2)
     metriks (0.9.9.7)
@@ -121,18 +121,18 @@ GEM
       multi_json (~> 1.0)
       simplecov-html (~> 0.7.1)
     simplecov-html (0.7.1)
-    sinatra (1.3.6)
-      rack (~> 1.4)
-      rack-protection (~> 1.3)
-      tilt (~> 1.3, >= 1.3.3)
+    sinatra (1.4.7)
+      rack (~> 1.5)
+      rack-protection (~> 1.4)
+      tilt (>= 1.3, < 3)
     slop (3.4.6)
     statsd-ruby (1.3.0)
     thin (1.6.4)
       daemons (~> 1.0, >= 1.0.9)
       eventmachine (~> 1.0, >= 1.0.4)
       rack (~> 1.0)
-    thor (0.19.1)
-    tilt (1.4.1)
+    thor (0.19.4)
+    tilt (2.0.5)
     timecop (0.7.1)
     vegas (0.1.11)
       rack (>= 1.0.0)

qless.gemspec

@@ -36,7 +36,7 @@ language-specific extension will also remain up to date.
   s.require_paths = ['lib']
 
   s.add_dependency 'metriks', '~> 0.9'
-  s.add_dependency 'redis', '>= 2.2'
+  s.add_dependency 'redis', ['>= 2.2', '< 4']
   s.add_dependency 'rusage', '~> 0.2.0'
   s.add_dependency 'sentry-raven', '~> 0.4'
   s.add_dependency 'sinatra', '~> 1.3'