Update changelog.txt

- Add security section
- Add Travis CI

changelog.txt

@@ -1,9 +1,10 @@
 *** Pico Changelog ***
 
-2015.10.XX - version 1.0-beta
+2015.11.XX - version 1.0.0-beta.1
  * NOTE: This changelog only provides basic information about the enormous
-         changes introduced with Pico 1.0-beta. Please refer to the UPGRADE
+         changes introduced with Pico 1.0.0-beta.1. Please refer to the
-         section of the docs for details.
+         UGPRADE section of the docs for details.
+ * [Security] (9e2604a) Prevent content_dir breakouts using malicious URLs
  * [New] Pico is on its way to its first stable release!
  * [New] Provide pre-bundled releases
  * [New] Heavily expanded documentation (inline code docs, user docs, dev docs)
@@ -26,6 +27,8 @@
  * [New] #103: Providing access to `sub.md` even when the `sub` directory
          exists, provided that there is no `sub/index.md`
  * [New] #249: Support the `.twig` file extension for templates
+ * [New] #268, 269: Now using Travis CI; performing basic code tests and
+         implementing an automatic release process
  * [Changed] Complete code refactoring
  * [Changed] Source code now follows PSR code styling
  * [Changed] Replacing constants (e.g. `ROOT_DIR`) with constructor parameters