Update subliminal to 2.0.5

Also updates:
- appdirs-1.4.3
- babelfish-0.5.5
- beautifulsoup4-4.6.3
- certifi-2018.11.29
- chardet-3.0.4
- click-7.0
- decorator-4.3.0
- dogpile.cache-0.7.1
- enzyme-0.4.1
- guessit-3.0.3
- idna-2.8
- pbr-5.1.1
- pysrt-1.1.1
- python-dateutil-2.7.5
- pytz-2018.7
- rarfile-3.0
- rebulk-1.0.0
- requests-2.21.0
- six-1.12.0
- stevedore-1.30.0
- urllib3-1.24.1

libs/pytz/exceptions.py

@@ -0,0 +1,48 @@
+'''
+Custom exceptions raised by pytz.
+'''
+
+__all__ = [
+    'UnknownTimeZoneError', 'InvalidTimeError', 'AmbiguousTimeError',
+    'NonExistentTimeError',
+]
+
+
+class UnknownTimeZoneError(KeyError):
+    '''Exception raised when pytz is passed an unknown timezone.
+
+    >>> isinstance(UnknownTimeZoneError(), LookupError)
+    True
+
+    This class is actually a subclass of KeyError to provide backwards
+    compatibility with code relying on the undocumented behavior of earlier
+    pytz releases.
+
+    >>> isinstance(UnknownTimeZoneError(), KeyError)
+    True
+    '''
+    pass
+
+
+class InvalidTimeError(Exception):
+    '''Base class for invalid time exceptions.'''
+
+
+class AmbiguousTimeError(InvalidTimeError):
+    '''Exception raised when attempting to create an ambiguous wallclock time.
+
+    At the end of a DST transition period, a particular wallclock time will
+    occur twice (once before the clocks are set back, once after). Both
+    possibilities may be correct, unless further information is supplied.
+
+    See DstTzInfo.normalize() for more info
+    '''
+
+
+class NonExistentTimeError(InvalidTimeError):
+    '''Exception raised when attempting to create a wallclock time that
+    cannot exist.
+
+    At the start of a DST transition period, the wallclock time jumps forward.
+    The instants jumped over never occur.
+    '''