Added matplotlib to broken recipes list

#1900 logs failure

Author: inclement

ci/constants.py

@@ -56,6 +56,7 @@ class TargetPython(Enum):
     'websocket-client',
     'zeroconf',
     'zope',
+    'matplotlib',  # https://github.com/kivy/python-for-android/issues/1900
 ])
 BROKEN_RECIPES_PYTHON3 = set([
     'brokenrecipe',
@@ -77,6 +78,7 @@ class TargetPython(Enum):
     # mpmath package with a version >= 0.19 required
     'sympy',
     'vlc',
+    'matplotlib',  # https://github.com/kivy/python-for-android/issues/1900
 ])
 
 BROKEN_RECIPES = {