For rspec, clear in the around block instead of the before block

Due to hook order we clear on around instead of before. This is
because if we clear in before, before runs AFTER around does and
therefore overrides any redis based changes we make in the around
hook.

If we clear in around, we can make changes to redis in BOTH the
around and before hooks!

lib/fakeredis/rspec.rb

@@ -16,9 +16,10 @@
 
 RSpec.configure do |c|
 
-  c.before do    
+  c.around do |ex|
     Redis::Connection::Memory.reset_all_databases
     Redis::Connection::Memory.reset_all_channels
+    ex.run
   end
 
 end