Fix deprecation warning

[labrys]

DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.9 it will stop working

[codecov-io]

Codecov Report

Merging #1874 into develop will decrease coverage by 0.71%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #1874      +/-   ##
===========================================
- Coverage    92.56%   91.84%   -0.72%     
===========================================
  Files           53       53              
  Lines        10001    10001              
===========================================
- Hits          9257     9185      -72     
- Misses         744      816      +72

Impacted Files	Coverage Δ
botocore/awsrequest.py	92.13% <100%> (-6.23%)	⬇️
botocore/compat.py	68.5% <0%> (-25.42%)	⬇️
botocore/hooks.py	95.18% <0%> (-1.21%)	⬇️
botocore/handlers.py	96.45% <0%> (-0.48%)	⬇️
botocore/utils.py	97.81% <0%> (-0.17%)	⬇️
botocore/credentials.py	98.4% <0%> (-0.12%)	⬇️

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[BoboTiG]

You should use that kind of code to fix the CI and Python 2 errors:

try:
   from collections.abc import MutableMapping
except ImportError:
   from collections import MutableMapping

Ad then use MutableMapping in class declaration.

[BoboTiG]

My bad, it did no see that this is a duplicate of #1865.

[labrys]

Closing as duplicate