Deploy v3.1.0

[injoonH]

Features

• Enable search query and add from_view for top articles. PR #407 by @000wan.
• Add calendar. PR #430 by @Qndndn and @injoonH.
• Change SMTP provider. PR #431 by @DoyunShin.

Refactors

• Use PositiveIntegerField and PositiveSmallIntegerField. PR #401 by @injoonH.

Fixes

• Fix N+1 query problems about GET /articles PR #414 by @retroinspect.
• Fix N+1 query problems about GET /home and GET /boards. PR #418 by @retroinspect.

Docs

• Update README and define coding styles. PR #422 by @injoonH.

[DoyunShin]

PR merge하기전에 SMTP 서버에 Ara의 IP 주소 추가가 이루어져야 합니다.

[DoyunShin]

smtp에 ARA Prod서버 추가하였습니다.
혹시 모르니 prod python3에서 smtp로 보내는 테스트 진행 후 merge하는걸 추천합니다.

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

smtp = smtplib.SMTP("smtp-relay.gmail.com", 587)
smtp.starttls()
smtp.ehlo()

sender = "ara@sparcs.org"
to = "new-ara-team@sparcs.org"

msg = MIMEMultipart()
msg["From"] = sender
msg["To"] = to
msg["Subject"] = "SMTP Relay test from ARA Prod Server"
msg.attach(MIMEText("This is a test message from ARA Prod Server! YAY!"))

smtp.sendmail(sender, to, msg.as_string())
smtp.quit()

테스트 코드입니다.