Redirect routes with trailing slashes

See: https://github.com/hanami/router/issues/256

Gemfile

@@ -30,6 +30,7 @@ gem "gnuplot"
 gem "matrix"
 
 gem "rack-session"
+gem "rack-rewrite"
 
 gem "ruby-readability", require: "readability"
 gem "down"

Gemfile.lock

@@ -330,6 +330,7 @@ GEM
     que (2.3.0)
     racc (1.7.3)
     rack (2.2.8)
+    rack-rewrite (1.5.1)
     rack-session (1.0.1)
       rack (< 3)
     rack-test (2.1.0)
@@ -517,6 +518,7 @@ DEPENDENCIES
   pinboard!
   puma
   que
+  rack-rewrite
   rack-session
   rack-test
   rake

config.ru

@@ -12,4 +12,10 @@ use Rack::Session::Cookie,
     :expire_after => 3600*24,
     :secret => ENV["SESSION_SECRET"]
 
+require "rack/rewrite"
+use Rack::Rewrite do
+  # remove trailing slashes
+  r302 %r{(/.*)/(\?.*)?$}, "$1$2"
+end
+
 run Hanami.app