Update dependency auto-changelog to v2.2.0

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
auto-changelog	devDependencies	minor	2.1.0 -> 2.2.0

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Release Notes

CookPete/auto-changelog

v2.2.0

Compare Source

3 July 2020

• add --prepend option as altenative to prepend-token #172
• Fix bug when no existing tags #170

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Code Climate has analyzed commit 8a4784b and detected 0 issues on this pull request.

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[codecov]

Codecov Report

Merging #84 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master       #84   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           16        16           
  Lines          305       305           
  Branches        33        33           
=========================================
  Hits           305       305           

Flag	Coverage Δ
#unittests	100.00% <ø> (ø)

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