ORC-1080: Remove .travis.yml (#997)

### What changes were proposed in this pull request?

This PR aims to remove Travis CI from Apache ORC CIs.

### Why are the changes needed?

In these days, Travis CI takes 4 or more hours to run.
![](https://user-images.githubusercontent.com/9700541/148463375-beef2e9b-61c0-4fb1-bc8f-10b53b854b30.png)

ORC-1079 already provides the same test coverage in GitHub Action. So, we can remove `Travis CI`. safely.

### How was this patch tested?

Travis CI should not be invoked in this PR.

(cherry picked from commit bfd8fde)
Signed-off-by: Dongjoon Hyun <[email protected]>