Initial commit of flattened multiselect
Add more indices tests
Update jmespath with alternate merging behavior

Now there's a difference between 'foo' and 'foo[]',
where the flattening of lists happens in the '[]' operator.
Make index expressions in flatten expression consistent

The behavior is now consistent with wildcards.
Add more tests for the flattening operator
Add test for single element multiselect with flattening
Update the spec/grammar for list flattening
Add another index test
Merge branch 'non-wildcard' into develop

* non-wildcard:
  Add another index test
  Update the spec/grammar for list flattening
  Add test for single element multiselect with flattening
  Add more tests for the flattening operator
  Make index expressions in flatten expression consistent
  Update jmespath with alternate merging behavior
  Add more indices tests
  Initial commit of flattened multiselect