query for now - 1 minute for cw metrics

[robpickerill]

On occasions, see #512, the getmetricdata call can return no results as the metric data is not yet populated. This PR sets the query to query for the latest datapoint (max 1 datapoint) for now - 1 minute.

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[codecov-commenter]

Codecov Report

Merging #536 (5135f61) into develop (170b400) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           develop      #536   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           42        42           
  Lines         3022      3022           
  Branches       451       451           
=========================================
  Hits          3022      3022           

Impacted Files	Coverage Δ
awslimitchecker/services/base.py	100.00% <ø> (ø)

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[jantman]

This has been released in 12.0.0, which is now live on PyPI and Docker Hub. Thank you so much, and apologies for the delay!