Add relative path sensitivity to input directory

[firthl]

Related to: https://github.com/trustin/sphinx-gradle-plugin/issues/12

[firthl]

I wanted to update the tests to catch the directory change scenario, i.e:

• run the first task
• change input location
• run second time
• check the second run was taken from the cache

https://docs.gradle.org/current/javadoc/org/gradle/api/tasks/TaskState.html#getUpToDate--

I couldn't see an obvious way of getting a clean cache from the project builder before doing the first run - and without that step we won't know whether the second run is taken from a previous attempt at running the tests.

[trustin]

Just published 2.6.1. Please let me know if the problem is gone. :bowing_man:

[firthl]

That was quick - thanks. :)