PyUP - Dependency Update Scheduled daily dependency update on wednesday (#851)

* Pin scikit-learn to latest version 0.20.0

* Update requirements.txt

* Update CHANGELOG.md

Author: pyup-bot

CHANGELOG.md

@@ -79,6 +79,7 @@ To release a new version, please update the changelog as followed:
 - yapf>=0.22,<0.24 => yapf>=0.22,<0.25 (PR #829)
 - sphinx>=1.7,<1.8 => sphinx>=1.7,<1.9 (PR #842)
 - matplotlib>=2.2,<2.3 => matplotlib>=2.2,<3.1 (PR #845)
+- scikit-learn>=0.19,<0.20 => scikit-learn>=0.19,<0.21 (PR #851)
 
 ### Deprecated
 

requirements/requirements.txt

@@ -4,7 +4,7 @@ matplotlib>=2.2,<3.1
 numpy>=1.14,<1.16
 progressbar2>=3.38,<3.39
 requests>=2.19,<2.20
-scikit-learn>=0.19,<0.20
+scikit-learn>=0.19,<0.21
 scikit-image>=0.14,<0.15
 scipy>=1.1,<1.2
 tqdm>=4.23,<4.26