It looks like LinkedIn pfCertFuture as the date a certificate expires.

We were using to indicate the date a course ended.  Better to remove it,
since edX certificates don't really expire.

lms/djangoapps/linkedin/management/commands/linkedin_mailusers.py

@@ -90,7 +90,6 @@ class Command(BaseCommand):
             ('pfCertificationUrl', certificate.download_url),
             ('pfLicenseNo', certificate.course_id),
             ('pfCertStartDate', course.start.strftime('%Y%mI')),
-            ('pfCertFuture', certificate.created_date.strftime('%Y%m')),
             ('_mSplash', '1'),
             ('trk', tracking_code),
             ('startTask', 'CERTIFICATION_NAME'),

lms/djangoapps/linkedin/management/commands/tests/test_mailusers.py

@@ -166,5 +166,5 @@ class MailusersTests(TestCase):
             'pfCertificationName=TestX%2FIntro101&pfAuthorityName=edX&'
             'pfAuthorityId=0000000&'
             'pfCertificationUrl=http%3A%2F%2Ftest.foo%2Ftest&pfLicenseNo=TEST1&'
-            'pfCertStartDate=201005I&pfCertFuture=201008&_mSplash=1&'
+            'pfCertStartDate=201005I&_mSplash=1&'
             'trk=eml-prof-TestX-1-T&startTask=CERTIFICATION_NAME&force=true')