implemented redux-logger given an environmental variable

[tiagofilipe12]

In this PR implemented a check for an environmental variable that changes the middlewares within lib/watermill.js. If REDUX_LOGGER=1 in environment the pipeline will execute redux-logger.
Also redux-logger package was updated in this PR.

[codecov-io]

Codecov Report

Merging #61 into master will increase coverage by 0.01%.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##           master      #61      +/-   ##
==========================================
+ Coverage   80.64%   80.66%   +0.01%     
==========================================
  Files          36       36              
  Lines         806      812       +6     
  Branches       99      100       +1     
==========================================
+ Hits          650      655       +5     
- Misses        156      157       +1

Impacted Files	Coverage Δ
lib/watermill.js	94.73% <85.71%> (-5.27%)	⬇️

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