Add periods to these exception messages.

voussoirkit/bytestring.py

@@ -105,13 +105,13 @@ def parsebytes(string):
 
     matches = re.findall(r'[\d\.-]+', string)
     if len(matches) == 0:
-        raise ValueError('No numbers found')
+        raise ValueError('No numbers found.')
     if len(matches) > 1:
-        raise ValueError('Too many numbers found')
+        raise ValueError('Too many numbers found.')
     byte_value = matches[0]
 
     if not string.startswith(byte_value):
-        raise ValueError('Number is not at start of string')
+        raise ValueError('Number is not at start of string.')
 
     # if the string has no text besides the number, just return that int.
     string = string.replace(byte_value, '')