Release 0.4.0

Author: JohanMabille

README.md

@@ -30,6 +30,7 @@ conda install -c conda-forge xtensor-python
 | `xtensor-python`  | `xtensor`  |  `pybind11` |
 |-------------------|------------|-------------|
 | master            |   0.5.0    | ^2.0.0      |
+| 0.4.0             |   0.5.0    | ^2.0.0      |
 | 0.3.0             |  ^0.4.1    | ^2.0.0      |
 | 0.2.0             |  ^0.2.1    | ^1.8.1      |
 | 0.1.0             |  ^0.1.1    | ^1.8.1      |