Fix: Do not require composer.json to be writable when using --dry-run option

[localheinz]

This PR

• removes the requirement for composer.json to be writable when using the --dry-run option

[codecov]

Codecov Report

Merging #177 into 1.x will not change coverage.
The diff coverage is 100%.

@@            Coverage Diff            @@
##                1.x     #177   +/-   ##
=========================================
  Coverage     82.68%   82.68%           
- Complexity       36       37    +1     
=========================================
  Files             2        2           
  Lines           179      179           
=========================================
  Hits            148      148           
  Misses           31       31

Impacted Files	Coverage Δ	Complexity Δ
src/Command/NormalizeCommand.php	87.05% <100%> (ø)	34 <0> (+1)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c4062e2...2c3092e. Read the comment docs.