Simplify date parsing (#195)

Create common functions parse_date, parse_month_year_date and parse_datetime.

Those functions support trying multiple formats, and come with default formats lists that support most of the date format encountered so far.

Notable change: year-month dates are now set to the end of month (impacted couchbase-server and ibm-aix).

src/confluence.py

@@ -1,6 +1,6 @@
 from requests_html import HTMLSession
+from common import dates
 from common import endoflife
-from datetime import datetime
 
 """Fetch Confluence versions with their dates from the Atlassian Website.
 
@@ -11,13 +11,7 @@ because the page needs JavaScript to render correctly.
 PRODUCT = 'confluence'
 URL = 'https://www.atlassian.com/software/confluence/download-archives'
 
-
-def parse_date(text):
-    return datetime.strptime(text, "%d-%b-%Y").strftime("%Y-%m-%d")
-
-
 print(f"::group::{PRODUCT}")
-
 session = HTMLSession()
 r = session.get(URL)
 r.html.render(sleep=1, scrolldown=3)
@@ -25,7 +19,8 @@ r.html.render(sleep=1, scrolldown=3)
 versions = {}
 for version_block in r.html.find('.versions-list'):
     version = version_block.find('a.product-versions', first=True).attrs['data-version']
-    date = parse_date(version_block.find('.release-date', first=True).text)
+    date_text = version_block.find('.release-date', first=True).text
+    date = dates.parse_date(date_text).strftime('%Y-%m-%d')
     print(f"{version}: {date}")
     versions[version] = date