Add logger module

[astrochun]

Closes #1

• [x] Bump version: v0.2.0 -> v0.3.0

• Add requirements.txt [ci skip]

• Add logger module

• Add unit tests for logger

• Add requirements in setup.py

• Add requests to requirements.txt

• Add docs for logger module [docs only]

• Add logger module to itemized list [docs only]

• Add use examples for logger module in execution.rst

• Add comment in logger module

• Update CHANGELOG.md [ci skip]