Feature/add kinesis analytics event

[vinujohn]

Added event and response for Kinesis Analytics output delivery.

Followed structure as defined here: https://docs.aws.amazon.com/kinesisanalytics/latest/dev/how-it-works-output-lambda.html

Naming of event and response was copied from .NET and Java: https://docs.aws.amazon.com/kinesisanalytics/latest/dev/how-it-works-output-lambda-functions.html

Added tests. Refactored existing tests by moving common readJsonFile from dyanamodb_test.go into test package

Reference issue: #99

[codecov-io]

Codecov Report

Merging #169 into master will decrease coverage by 0.07%.
The diff coverage is 60%.

@@            Coverage Diff             @@
##           master     #169      +/-   ##
==========================================
- Coverage   70.33%   70.25%   -0.08%     
==========================================
  Files          18       19       +1     
  Lines         691      696       +5     
==========================================
+ Hits          486      489       +3     
- Misses        165      166       +1     
- Partials       40       41       +1

Impacted Files	Coverage Δ
events/test/readjson.go	60% <60%> (ø)

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[bmoffatt]

Thanks!