Removed Twitter Referances (#155)

conf.py

@@ -35,7 +35,6 @@
 PROJECT_REPOSITORY = "https://github.com/PlasmaPy/PlasmaPy"
 CHAT = "https://app.element.io/#/room/#plasmapy:openastronomy.org"
 TELECON_CALENDAR = "https://calendar.google.com/calendar/embed?src=c_sqqq390s24jjfjp3q86pv41pi8%40group.calendar.google.com&ctz=America%2FNew_York"
-TWITTER = "https://twitter.com/plasmapy"
 YOUTUBE_CHANNEL = "https://www.youtube.com/channel/UCSH6qzslhqIZKTAJmHPxIxw"
 JITSI = "https://meet.jit.si/plasmapy"
 ZOOM = "https://zoom.us/j/91633383503?pwd=QWNkdHpWeFhrYW1vQy91ODNTVG5Ndz09"
@@ -180,7 +179,6 @@
                 (TELECON_CALENDAR, "Calendar"),
                 ("/meetings", "Meetings"),
                 (FACEBOOK, "Facebook"),
-                (TWITTER, "Twitter"),
                 (YOUTUBE_CHANNEL, "YouTube"),
             ),
             "Community",
@@ -992,7 +990,6 @@
     '- <a href="{repo}">GitHub</a> '
     "- {license} "
     '- <a href="{facebook}">Facebook</a> '
-    '- <a href="{twitter}">Twitter</a> '
     '- <a href="{youtube}">YouTube</a> '
     '- <a href="{chat}">Chat</a> '
     '- <a href="{benchmarks}">Benchmarks</a> '
@@ -1021,7 +1018,6 @@
             "date": time.gmtime().tm_year,
             "license": LICENSE,
             "facebook": FACEBOOK,
-            "twitter": TWITTER,
             "youtube": YOUTUBE_CHANNEL,
             "chat": CHAT,
             "benchmarks": BENCHMARKS,