[Snyk] Security upgrade postmark from 4.0.2 to 4.0.5

[killmenot]

Snyk has created this PR to fix 5 vulnerabilities in the npm dependencies of this project.

Snyk changed the following file(s):

• package.json
• package-lock.json

Vulnerabilities that will be fixed with an upgrade:

	Issue	Score
	Server-side Request Forgery (SSRF) SNYK-JS-AXIOS-7361793	801
	Improper Input Validation SNYK-JS-FOLLOWREDIRECTS-6141137	686
	Information Exposure SNYK-JS-FOLLOWREDIRECTS-6444610	646
	Prototype Pollution SNYK-JS-AXIOS-6144788	589
	Regular Expression Denial of Service (ReDoS) SNYK-JS-AXIOS-6124857	586

---

Important

• Check the changes in this PR to ensure they won't cause issues with your project.
• Max score is 1000. Note that the real score may have changed since the PR was raised.
• This PR was automatically created by Snyk using the credentials of a real user.

---

Note: You are seeing this because you or someone else with access to this repository has authorized Snyk to open fix PRs.

For more information:
🧐 View latest project report
📜 Customise PR templates
🛠 Adjust project settings
📚 Read about Snyk's upgrade logic

---

Learn how to fix vulnerabilities with free interactive lessons:

🦉 Regular Expression Denial of Service (ReDoS)
🦉 Prototype Pollution
🦉 Server-side Request Forgery (SSRF)
🦉 More lessons are available in Snyk Learn

[coveralls]

coverage: 93.857%. remained the same
when pulling ec5ac58 on snyk-fix-e47712f7a0fb8cd7c97472b285577594
into c2128af on master.