By default, dune utop tries to make a toplevel for the current directory:

  $ echo 'exit 0;;' | dune utop --root lib-in-root | grep -v 'version'
  Entering directory 'lib-in-root'
  
  # 


Utop will load libs recursively:

  $ echo 'exit 0;;' | dune utop --root nothing-in-root | grep -v 'version'
  Entering directory 'nothing-in-root'
  
  # 


The message where the library path does not exist is different:

  $ dune utop --root nothing-in-root does-not-exist
  Cannot find directory: does-not-exist
  [1]

By default, dune utop tries to make a toplevel for the current directory:

  $ echo 'exit 0;;' | dune utop --root lib-in-root . -- -init "" | grep -v 'version'
  Entering directory 'lib-in-root'
  
  Init file not found: "".
  # 


Utop will load libs recursively:

  $ echo 'exit 0;;' | dune utop --root nothing-in-root . -- -init "" | grep -v 'version'
  Entering directory 'nothing-in-root'
  
  Init file not found: "".
  # 


The message where the library path does not exist is different:

  $ dune utop --root nothing-in-root does-not-exist . -- -init ""
  Cannot find directory: does-not-exist
  [1]

Add non existant init files to utop tests
Add non existant init files to utop tests

Signed-off-by: Rudi Grinberg <4c46c202a3b8207ad5740134b125aae40c6c67a8@gmail.com>
