ReadError exception fails to mention the file generating the error.

[ssbarnea]

While the error causing the exception seems to be caused by #218 what makes it much worse is the it produces an output which makes impossible to identify the filename causing the problem:

$ yamllint -f parsable .                                                                                                                                                  Traceback (most recent call last):
File "/Users/ssbarnea/.pyenv/versions/3.7.6/bin/yamllint", line 10, in <module>
sys.exit(run())
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yamllint/cli.py", line 185, in run
no_warn=args.no_warnings)
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yamllint/cli.py", line 91, in show_problems
for problem in problems:
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yamllint/linter.py", line 198, in _run
syntax_error = get_syntax_error(buffer)
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yamllint/linter.py", line 179, in get_syntax_error
list(yaml.parse(buffer, Loader=yaml.BaseLoader))
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yaml/__init__.py", line 73, in parse
loader = Loader(stream)
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yaml/loader.py", line 14, in __init__
Reader.__init__(self, stream)
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yaml/reader.py", line 74, in __init__
self.check_printable(stream)
File "/Users/ssbarnea/.pyenv/versions/3.7.6/lib/python3.7/site-packages/yaml/reader.py", line 144, in check_printable
'unicode', "special characters are not allowed")
yaml.reader.ReaderError: unacceptable character #x001b: special characters are not allowed
in "<unicode string>", position 60
FAIL: 1

At minimum, the filename must be mentioned.