Add MonadFail instance for UpdateParser

[vyorkin]

fixes #26

[swamp-agr]

✅ 8.10.1 build successful.
✅ 8.8.3 build successful.
❌ 8.6.5 build failed:

src/Telegram/Bot/Simple/UpdateParser.hs:30:10: error:
    Not in scope: type constructor or class ‘MonadFail’
    Perhaps you meant ‘MonadFix’ (imported from Control.Monad.Reader)
   |
30 | instance MonadFail UpdateParser where
   |          ^^^^^^^^^
cabal: Failed to build telegram-bot-simple-0.3.0 (which is required by
exe:example-todo-bot from telegram-bot-simple-0.3.0 and exe:example-echo-bot
from telegram-bot-simple-0.3.0).

@vyorkin could you please fix the build by adding {-# LANGUAGE CPP #-} on top of the file and replacing your code with something like this (see below)?

instance Monad UpdateParser where
  return = pure
  UpdateParser x >>= f = UpdateParser (\u -> x u >>= flip runUpdateParser u . f)

#if MIN_VERSION_base(4,13,0)
instance MonadFail UpdateParser where
  fail _ = empty
#endif

[swamp-agr]

@vyorkin thank you for contribution!