Add tests for amendment log, and a bit code reformat

[kuenishi]

RIAK-1212

• Add a function riak_cs_access:flush_to_log/2,3 which outputs one access key and value supposed to be put into moss.access.
• flush_to_log/2 folds around all ets entries and outputs all of them to each line, with JSON encoded
• flush_to_log/3 outputs single key and value to log.
• The test works as follows:
  • write some data to CS
  • kill all Riak process
  • try to flush the access stats
  • check Riak CS log and verifies whether correct log is updated or not.

[shino]

I want some description about the change. One with just one or two lines is fine.

[kuenishi]

• Add a function riak_cs_access:flush_to_log/2,3 which outputs one access key and value supposed to be put into moss.access.
• flush_to_log/2 folds around all ets entries and outputs all of them to each line, with JSON encoded
• flush_to_log/3 outputs single key and value to log.
• The test works as follows:
  • write some data to CS
  • kill all Riak process
  • try to flush the access stats
  • check Riak CS log and verifies whether correct log is updated or not.
• And some code reformatting added.

[shino]

Copied the above comment to the PR description.

[ksauzz]

• manual test: https://gist.github.com/ksauzz/115ded58df82d39dba9e
• riak_test

[kuenishi]

@borshop merge