UX: Stop using fixed-width font to render github issue description

UX: Stop using fixed-width font to render github issue description

Bump onebox version

diff --git a/Gemfile b/Gemfile
index 7bafe7b..645bbc5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -50,7 +50,7 @@ gem 'redis-namespace'
 
 gem 'active_model_serializers', '~> 0.8.3'
 
-gem 'onebox', '1.9.14'
+gem 'onebox', '1.9.15'
 
 gem 'http_accept_language', '~>2.0.5', require: false
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 98adbbe..0945202 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -245,7 +245,7 @@ GEM
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
       rack
-    onebox (1.9.14)
+    onebox (1.9.15)
       htmlentities (~> 4.3)
       moneta (~> 1.0)
       multi_json (~> 1.11)
@@ -501,7 +501,7 @@ DEPENDENCIES
   omniauth-oauth2
   omniauth-openid
   omniauth-twitter
-  onebox (= 1.9.14)
+  onebox (= 1.9.15)
   openid-redis-store
   parallel_tests
   pg

GitHub sha: e7cc7def