URL Cleanup (#99)

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 But Review Recommended
These URLs were fixed, but the https status was not OK. However, the https status was the same as the http request or http redirected to an https URL, so they were migrated. Your review is recommended.

* [ ] http://compose.docker.io/ (UnknownHostException) with 1 occurrences migrated to:
  https://compose.docker.io/ ([https](https://compose.docker.io/) result UnknownHostException).
* [ ] http://www.puppycrawl.com/dtds/suppressions_1_1.dtd (404) with 2 occurrences migrated to:
  https://www.puppycrawl.com/dtds/suppressions_1_1.dtd ([https](https://www.puppycrawl.com/dtds/suppressions_1_1.dtd) result 404).

## 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://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html with 3 occurrences migrated to:
  https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html ([https](https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html) result 200).
* [ ] http://contributor-covenant.org with 1 occurrences migrated to:
  https://contributor-covenant.org ([https](https://contributor-covenant.org) result 301).
* [ ] http://contributor-covenant.org/version/1/3/0/ with 1 occurrences migrated to:
  https://contributor-covenant.org/version/1/3/0/ ([https](https://contributor-covenant.org/version/1/3/0/) result 301).
* [ ] http://plugins.jetbrains.com/plugin/6546 with 3 occurrences migrated to:
  https://plugins.jetbrains.com/plugin/6546 ([https](https://plugins.jetbrains.com/plugin/6546) result 301).
* [ ] http://eclipse.org with 1 occurrences migrated to:
  https://eclipse.org ([https](https://eclipse.org) result 302).
* [ ] http://eclipse.org/m2e/ with 2 occurrences migrated to:
  https://eclipse.org/m2e/ ([https](https://eclipse.org/m2e/) result 302).
* [ ] http://www.springsource.com/developer/sts with 1 occurrences migrated to:
  https://www.springsource.com/developer/sts ([https](https://www.springsource.com/developer/sts) result 302).

.github/CONTRIBUTING.md

@@ -28,7 +28,7 @@ added after the original pull request but before a merge.
   you can import formatter settings using the
   `eclipse-code-formatter.xml` file from the
   [Spring Cloud Build](https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/spring-cloud-dependencies-parent/eclipse-code-formatter.xml) project. If using IntelliJ, you can use the
-  [Eclipse Code Formatter Plugin](http://plugins.jetbrains.com/plugin/6546) to import the same file.
+  [Eclipse Code Formatter Plugin](https://plugins.jetbrains.com/plugin/6546) to import the same file.
 * Make sure all new `.java` files to have a simple Javadoc class comment with at least an
   `@author` tag identifying you, and preferably at least a paragraph on what the class is
   for.
@@ -40,6 +40,6 @@ added after the original pull request but before a merge.
 * A few unit tests would help a lot as well -- someone has to do it.
 * If no-one else is using your branch, please rebase it against the current master (or
   other target branch in the main project).
-* When writing a commit message please follow [these conventions](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html),
+* When writing a commit message please follow [these conventions](https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html),
   if you are fixing an existing issue please add `Fixes gh-XXXX` at the end of the commit
   message (where XXXX is the issue number).