test (Suite): modify populate index test
test (Suite): modify populate index test

refactor formatting, white-space and variables name
(suite): populate index
modify (spec 1) and (spec 2)
add (spec 3): should verify the index maps the string keys
to the correct objects in the JSON array

andela-abankole/inverted-index,andela-abankole/inverted-index,andela-abankole/inverted-index