Don't build with Nim v1.4, building with v1.2 and v1.6 should be enough.
Don't manually run `brew update` because `brew` will automatically do that on
an as-needed basis when running `brew install`.
Per SQLite's docs, `sqlite3_bind_blob(s, n.cint, nil, 0.cint, nil)` is
equivalent to `sqlite3_bind_null(s, n.cint)` but the intent of the latter is
clearer.
