URL Cleanup (#30)

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://creativecommons.org/licenses/by-nd/3.0/ with 1 occurrences migrated to:
  https://creativecommons.org/licenses/by-nd/3.0/ ([https](https://creativecommons.org/licenses/by-nd/3.0/) result 200).
* [ ] http://docs.spring.io/spring-boot/docs/ with 1 occurrences migrated to:
  https://docs.spring.io/spring-boot/docs/ ([https](https://docs.spring.io/spring-boot/docs/) result 200).
* [ ] http://docs.spring.io/spring/docs/ with 1 occurrences migrated to:
  https://docs.spring.io/spring/docs/ ([https](https://docs.spring.io/spring/docs/) result 200).

LICENSE.writing.txt

@@ -1 +1 @@
-Except where otherwise noted, this work is licensed under http://creativecommons.org/licenses/by-nd/3.0/
+Except where otherwise noted, this work is licensed under https://creativecommons.org/licenses/by-nd/3.0/

README.adoc

@@ -1,7 +1,7 @@
 :spring_version: current
 :spring_boot_version: 2.1.3.RELEASE
-:Component: http://docs.spring.io/spring/docs/{spring_version}/javadoc-api/org/springframework/stereotype/Component.html
-:SpringApplication: http://docs.spring.io/spring-boot/docs/{spring_boot_version}/api/org/springframework/boot/SpringApplication.html
+:Component: https://docs.spring.io/spring/docs/{spring_version}/javadoc-api/org/springframework/stereotype/Component.html
+:SpringApplication: https://docs.spring.io/spring-boot/docs/{spring_boot_version}/api/org/springframework/boot/SpringApplication.html
 :toc:
 :icons: font
 :source-highlighter: prettify