Do not match second slash and dot in DOI (#1)

They are the only reserved characters, according to
https://www.doi.org/doi_handbook/2_Numbering.html#2.5

Cf. mediawiki-utilities#7

Author: Xarvalus

Diff for: mwcites/extractors/doi.py

@@ -14,7 +14,7 @@
 TAGS_RE = re.compile(r'<(/\s*)?(' + '|'.join(HTML_TAGS) + ')(\s[^>\n\r]+)?>', re.I)
 
 '''
-DOI_RE = re.compile(r'\b(10\.\d+/[^\s\|\]\}\?\,]+)')
+DOI_RE = re.compile(r'\b(10\.\d+/[^\./\s\|\]\}\?\,]+)')
 
 def extract_regex(text):
     for match in DOI_RE.finditer(text):