Use public Github links i.e. not requiring an SSH user

Author: mattheworiordan

pom.xml

@@ -20,9 +20,9 @@
     </license>
   </licenses>
   <scm>
-    <connection>scm:git:git@github.com:ably/ably-java</connection>
-    <developerConnection>scm:git:git@github.com:ably/ably-java&lt;/developerConnection</developerConnection>
-    <url>scm:git:git@github.com:ably/ably-java</url>
+    <connection>scm:git:https://github.com/ably/ably-java</connection>
+    <developerConnection>scm:git:git@github.com:ably/ably-java</developerConnection>
+    <url>scm:git:https://github.com/ably/ably-java</url>
   </scm>
   <issueManagement>
     <system>Github</system>