fix: use TUTOR_VERSION for a better version management

setup.py

@@ -3,6 +3,7 @@
 from setuptools import setup, find_packages
 
 here = os.path.abspath(os.path.dirname(__file__))
+TUTOR_VERSION = ">=16.0.0,<17.0.0"
 
 with io.open(os.path.join(here, "README.rst"), "rt", encoding="utf8") as f:
     readme = f.read()
@@ -33,10 +34,10 @@
     packages=find_packages(exclude=["tests*"]),
     include_package_data=True,
     python_requires=">=3.8",
-    install_requires=["tutor>=16.0.0,<17.0.0", "requests"],
+    install_requires=[f"tutor{TUTOR_VERSION}" , "requests"],
     extras_require={
         "dev": [
-            "tutor[dev]>=16.0.0,<17.0.0",
+            f"tutor[dev]{TUTOR_VERSION}" ,
             "types-requests==2.31.0.0"
         ],
     },