0.3.1

This small release only contains one patch will cause a new upload
to be automatically be created when using the `TusClient#resumeOrCreateUpload`
method and if the original upload cannot be found anymore since the tus server
sends back the `404 Not Found` status code (see tus#3).

This minor release contains some pretty neat features mostly focusing

on a better uploading experience:

* Added `TusExecutor` for automatic retries and resumes
* Added `@NotNull` and `@Nullable` annotations for some methods
* Added `TusClient#setHeaders` for custom headers in requests
* Added filename into metadata by default
* Added `Expect: 100-continue` header for faster error handling

* Test response header's values for not being null before accessing t…

…heir length

  to prevent NullPointerException.

This minor release adds the TusUploader#setChunkSize() and

TusUploader#uploadChunk() methods while deprecating the original
TusUploader#uploadChunk(int) method in order to reduce memory
allocations by resuing internal buffers.

Add dependecy for example project

Use pomVersion for variable in Gradle

Fix deployment to Bintray

Use mocking server for Creation responses

Use -F option for uploading files