Update TravisCI Configuration

Add HHVM to the list of PHP versions to run tests against.
Update TravisCI Configuration

Update Composer to the latest version before running tests. HipHop cannot run Composer Phar on Travis CI.
Rename Example Event

Rename the example event class to 'Basic' like the basic collection is. Makes it more obvious that the class is an example, rather than a required part of the library.
Merge branch 'basic-event'
Update Unit Tests

Update the appropriate unit tests to start using the Basic event class, instead of the old Event class.
Merge branch 'basic-event'
Fix Misreferenced Method Call

Change the call calendar getStrictDates() helper method from the factory method setStrictDates() to getStrictDates(), regarding comments made in pull request #33.
Add Unit Test

Add the unit test 'strictDates' to the core calendar test case. Ensure that the 'strict_dates' option can be set and retrieved.
Merge branch 'master' into custom-interval-on-hour-period-iteration