Minor Cython upgrade.

requirements_dev.txt

@@ -1,5 +1,5 @@
 CoilMQ>=1.0.1
-Cython==0.29
+Cython==0.29.6
 Flask>=0.12.2
 HiYaPyCo>=0.4.11
 Pillow>=4.3.0

setup.py

@@ -16,7 +16,7 @@ from os import path
 import lakesuperior
 
 # Use this version to build C files from .pyx sources.
-CYTHON_VERSION='0.29'
+CYTHON_VERSION='0.29.6'
 
 KLEN = 5 # TODO Move somewhere else (config?)