Merge pull request #52 from Hi-king/fix/too_strict_dependencies

Fix too strict dependencies

Author: vaaaaanquish

setup.py

@@ -9,16 +9,16 @@
 install_requires = [
     'luigi',
     'gokart>=0.1.20',
-    'python-dateutil==2.7.5',
+    'python-dateutil>=2.7.5',
     'pandas',
     'scipy',
     'numpy',
     'gensim',
     'scikit-learn',
     'tensorflow>=1.13.1, <2.0',
     'tqdm',
-    'optuna==0.6.0',
-    'docutils==0.15' # to avoid dependency conflict
+    'docutils==0.15', # to avoid dependency conflict
+    'optuna>=0.6.0',
 ]
 
 setup(