Refactored Boards with Promises

Refactored all of boards, validation and tests included, to use
promises.
Updated posts/threads to utilize promises

Updated all the functions in posts and threads to utilize promises. All
tests were also updated to be mostly promise based as well. Unnecessary
helper functions were also removed. Validation files were also updated
to use promises instead of callbacks.
Bug fixes, fault tolerance, benchmarks

Added bug fixes in posts/index and threads/index to pass the linter.
Added more catch statements in seed for better fault tolerance.
Updated the bnechmark file to use the updated promises coming out of all
the models.