Merge pull request #121 from joecummings/patch-1

Update Installation.rst

Author: cosmic-cortex

docs/source/content/overview/Installation.rst

@@ -5,7 +5,7 @@ modAL requires
    * Python >= 3.5
    * NumPy >= 1.13
    * SciPy >= 0.18
-   * scikit-learn >= 0.18
+   * scikit-learn >= 0.22
 
 You can install modAL directly with pip: