Merge pull request #84 from alicevision/fix/poparturl

[doc] Update Popart link

Author: fabiencastan

README.md

@@ -135,7 +135,7 @@ If you use PopSift for your publication, please cite us as:
 
 ## Acknowledgements
 
-PopSift was developed within the project [POPART](http://www.popartproject.eu), which has been funded by the European Commission in the Horizon 2020 framework.
+PopSift was developed within the project [POPART](https://alicevision.org/popart), which has been funded by the [European Commission in the Horizon 2020](https://cordis.europa.eu/project/id/644874) framework.
 
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