It seems the test directory backtrace line is output with a / before it,...

It seems the test directory backtrace line is output with a / before it, thereby previously making it not match the regex. Support APP_DIRS that have backtrace lines maybe beginning with /. [#4277 state:resolved]
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

railties/lib/rails/backtrace_cleaner.rb

@@ -13,7 +13,7 @@ def initialize
 
       add_gem_filters
 
-      add_silencer { |line| !APP_DIRS.any? { |dir| line =~ /^#{dir}/ } }
+      add_silencer { |line| !APP_DIRS.any? { |dir| line =~ /^\/?#{dir}/ } }
     end
 
     private