try pyproject.toml then flit.ini

[jwkvam]

Fixes #215

Do not have any unit tests, but appears to work through my manual testing.

Errors will look something like this:

Traceback (most recent call last):
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/installfrom.py", line 117, in install_local
    deps='production').install()
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/install.py", line 106, in __init__
    self.ini_info = inifile.read_pkg_ini(ini_path)
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/inifile.py", line 56, in read_pkg_ini
    cp = _read_pkg_ini(path)
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/inifile.py", line 156, in _read_pkg_ini
    with path.open(encoding='utf-8') as f:
  File "/Users/jacques/miniconda/lib/python3.6/pathlib.py", line 1181, in open
    opener=self._opener)
  File "/Users/jacques/miniconda/lib/python3.6/pathlib.py", line 1035, in _opener
    return self._accessor.open(self, flags, mode)
  File "/Users/jacques/miniconda/lib/python3.6/pathlib.py", line 387, in wrapped
    return strfunc(str(pathobj), *args)
FileNotFoundError: [Errno 2] No such file or directory: '/var/folders/gd/p_8rmvg56j39gd6lnkb7_51h0000gn/T/tmph97psynz/pyGAM-master/flitx.ini'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/jacques/miniconda/bin/flit", line 4, in <module>
    main()
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/__init__.py", line 127, in main
    sys.exit(installfrom(args.location, user=args.user, python=args.python))
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/installfrom.py", line 130, in installfrom
    return install_local(fetch(*parse_address(address)), user=user, python=python)
  File "/Users/jacques/miniconda/lib/python3.6/site-packages/flit/installfrom.py", line 121, in install_local
    raise FileNotFoundError('Neither {} found'.format(' nor '.join(ininames))) from exc
FileNotFoundError: Neither pyproject.toml nor flitx.ini found

[takluyver]

Thanks, but I think it would be better to check explicitly (p / ini_name).is_file() - this avoids accidentally catching anything else that might raise a FileNotFoundError while installing the package.

[jwkvam]

@takluyver thanks for the suggestion, let me know what you think about the update.

[takluyver]

Looks good, thanks!