Exclude Mint.HTTP module from warnings

[aleDsz]

==> kino_db
Compiling 4 files (.ex)
warning: Mint.HTTP.connect/3 is undefined (module Mint.HTTP is not available or is yet to be defined)
  lib/kino_db/connection_cell.ex:395: KinoDB.ConnectionCell.running_on_google_metadata?/0

warning: Mint.HTTP.set_mode/2 is undefined (module Mint.HTTP is not available or is yet to be defined)
  lib/kino_db/connection_cell.ex:396: KinoDB.ConnectionCell.running_on_google_metadata?/0

Generated kino_db app

[josevalim]

Wait, do we use @compile {:no_warn_undefined, ...} anywhere else in this project. If so, perhaps we should do the same in KinoDB.ConnectionCell. Otherwise this patch is good to go!

[wojtekmach]

Yeah, we have one occurrence:

lib/kino_db/sql_cell.ex
113:  @compile {:no_warn_undefined, {DBConnection, :connection_module, 1}}

+1 on standardising either way. :)