SGF-827 - URL Cleanup.

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).

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

* http://docs.oracle.com/javase/6/docs/api/ with 1 occurrences migrated to:
  https://docs.oracle.com/javase/6/docs/api/ ([https](https://docs.oracle.com/javase/6/docs/api/) result 200).
* http://docs.spring.io/spring-data-gemfire/docs/current/api/ with 1 occurrences migrated to:
  https://docs.spring.io/spring-data-gemfire/docs/current/api/ ([https](https://docs.spring.io/spring-data-gemfire/docs/current/api/) result 200).
* http://docs.spring.io/spring-data/commons/docs/current/api/index.html?index-all.html with 1 occurrences migrated to:
  https://docs.spring.io/spring-data/commons/docs/current/api/index.html?index-all.html ([https](https://docs.spring.io/spring-data/commons/docs/current/api/index.html?index-all.html) result 200).
* http://docs.spring.io/spring/docs/current/javadoc-api/ with 1 occurrences migrated to:
  https://docs.spring.io/spring/docs/current/javadoc-api/ ([https](https://docs.spring.io/spring/docs/current/javadoc-api/) result 200).
* http://logging.apache.org/log4j/1.2/apidocs/ with 1 occurrences migrated to:
  https://logging.apache.org/log4j/1.2/apidocs/ ([https](https://logging.apache.org/log4j/1.2/apidocs/) result 200).
* http://maven.apache.org/xsd/maven-4.0.0.xsd with 1 occurrences migrated to:
  https://maven.apache.org/xsd/maven-4.0.0.xsd ([https](https://maven.apache.org/xsd/maven-4.0.0.xsd) result 200).
* http://www.apache.org/licenses/LICENSE-2.0.txt with 1 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0.txt ([https](https://www.apache.org/licenses/LICENSE-2.0.txt) result 200).
* http://github.com/SpringSource/spring-gemfire with 2 occurrences migrated to:
  https://github.com/SpringSource/spring-gemfire ([https](https://github.com/SpringSource/spring-gemfire) result 301).
* http://repo.springsource.org/libs-snapshot with 1 occurrences migrated to:
  https://repo.springsource.org/libs-snapshot ([https](https://repo.springsource.org/libs-snapshot) result 301).
* http://www.springsource.org/spring-gemfire with 1 occurrences migrated to:
  https://www.springsource.org/spring-gemfire ([https](https://www.springsource.org/spring-gemfire) result 301).
* http://gemfire.docs.pivotal.io/docs-gemfire/latest/javadocs/japi/ with 1 occurrences migrated to:
  https://gemfire.docs.pivotal.io/docs-gemfire/latest/javadocs/japi/ ([https](https://gemfire.docs.pivotal.io/docs-gemfire/latest/javadocs/japi/) result 302).

These URLs were intentionally ignored.

* http://maven.apache.org/POM/4.0.0 with 2 occurrences
* http://www.w3.org/2001/XMLSchema-instance with 1 occurrences

Resolves gh-106.

samples/hello-world/build.gradle

@@ -10,7 +10,7 @@ apply plugin: 'application'
 
 repositories {
     // Public Spring artefacts
-    maven { url "http://repo.springsource.org/libs-snapshot" }
+    maven { url "https://repo.springsource.org/libs-snapshot" }
     mavenLocal()
 }