... Specifically:
 - resolveDefaultKnexfilePath(...)
 - resolveKnexFilePath(...)

This property is used when inferring the appropriate extension
for the migration files

... this way, we can be sure that the correct migrations are
being run.  (As opposed to a directory lookup error, or something
like that)

... Specifically: the default configuration for nyc causes it
to add ".ts" to the the `require.extensions` list.

The problem: Liftoff consults `require.extensions` when deciding
which modules need to be preloaded.  Since ".ts" is already on
the list, Liftoff decides that "ts-node" must have already been
preloaded.  Therefore, it hands control off to the Knex CLI
without ever registering Typescript support.  Consequently, the
Knex CLI will explode if it attempts to open a Knexfile that was
written in Typescript.

In other words: this error only occurs when `nyc` (or another
tool) modifies `require.extensions` before handing control over
to the Knex CLI.