Upgrade various dependencies

[Kami]

Just some house keeping.

It updates the following dependencies to the latest stable version.

General dependencies

• paramiko
• appscheduler
• pyyaml
• semver
• retrying
• kombu
• amqp
• networkx
• jsonschema
• sseclient
• jsonpath-rw

Dev / test dependencies

• pylint, astroid (done in a separate PR which fixes some lint issues)
• flake8 (done in a separate PR which fixes some lint issues)
• mock (done in a separate PR which fixes some lint issues)

I verified the checked and all the changes are backward compatible, but I still think it's better to merge this post v2.2.0.

[codecov-io]

Codecov Report

Merging #3189 into master will decrease coverage by -0.05%.
The diff coverage is 94.44%.

@@            Coverage Diff             @@
##           master    #3189      +/-   ##
==========================================
- Coverage   77.83%   77.78%   -0.05%     
==========================================
  Files         433      433              
  Lines       22398    22408      +10     
==========================================
- Hits        17433    17429       -4     
- Misses       4965     4979      +14

Impacted Files	Coverage Δ
st2client/st2client/commands/action.py	58.49% <ø> (ø)	✅
st2common/st2common/models/db/marker.py	100% <ø> (ø)	✅
st2api/st2api/controllers/resource.py	88.02% <ø> (+1.24%)	✅
st2common/st2common/content/bootstrap.py	0% <ø> (ø)	✅
st2common/st2common/models/db/rule.py	100% <ø> (ø)	✅
st2common/st2common/models/db/rbac.py	100% <ø> (ø)	✅
st2common/st2common/models/db/sensor.py	100% <ø> (ø)	✅
st2common/st2common/operators.py	84.8% <ø> (ø)	✅
st2common/st2common/models/db/rule_enforcement.py	76.67% <ø> (ø)	✅
st2common/st2common/models/db/action.py	100% <ø> (ø)	✅
... and 32 more

---

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[arm4b]

but I still think it's better to merge this post v2.2.0.

+:100:

[Kami]

This PR is obsolete now, will open a new one.