UnitTest warnings

[nsano-rururu]

It seems to have started appearing with the changes in prettytable 3.12.0.
https://github.com/prettytable/prettytable

./elastalert/alerts.py:9
../elastalert/alerts.py:9
../elastalert/alerts.py:9
../elastalert/alerts.py:9
../elastalert/alerts.py:9
  /home/elastalert/elastalert/alerts.py:9: DeprecationWarning: the 'MSWORD_FRIENDLY' constant is deprecated, use the 'TableStyle' enum instead
    from prettytable import MSWORD_FRIENDLY

../elastalert/alerts.py:10
../elastalert/alerts.py:10
../elastalert/alerts.py:10
../elastalert/alerts.py:10
../elastalert/alerts.py:10
  /home/elastalert/elastalert/alerts.py:10: DeprecationWarning: the 'ALL' constant is deprecated, use the 'HRuleStyle' and 'VRuleStyle' enums instead
    from prettytable import ALL

---

Below are some suggested solutions.

setup.py and requirements.txt

prettytable>=3.10.0
to
prettytable>=3.12.0

alert.py

before

from prettytable import MSWORD_FRIENDLY
from prettytable import ALL

after

import prettytable
from prettytable import (
    HRuleStyle,
    TableStyle,
    VRuleStyle
)

before

text_table.set_style(MSWORD_FRIENDLY)

after

text_table.set_style(TableStyle.MSWORD_FRIENDLY)

before

text_table.hrules = ALL

after

text_table.hrules = HRuleStyle.ALL

before

text_table.vrules = ALL

after

text_table.vrules = VRuleStyle.ALL

[jertel]

Resolved in #1599.