Define minimal version for bottle package.

danny0838 · danny0838 · commit e2a504e3f368 · 2019-03-30T00:01:33.000+08:00
diff --git a/setup.py b/setup.py
@@ -30,7 +30,7 @@
         ],
     python_requires='~=3.5',
     install_requires=[
-        "bottle",
+        "bottle >= 0.12",
         'commonmark >= 0.8',
         ],
     packages=find_packages(),
