Update README and requirements to make development install less brittle

Author: RaghuSpaceRajan

README.md

@@ -98,17 +98,25 @@ For continued usage of MDP Playground as it is in development, please continue r
 
 ### Production use
 We recommend using `conda` to manage environments. After setup of the environment, you can install MDP Playground in two ways:
+
 #### Manual
-To install MDP Playground manually, clone the repository and run:
+To install MDP Playground manually (this might be the preferred way if you want easy access to the included experiments), clone the repository and run:
 ```bash
+# If you just want to use the environments as in example.py:
+pip install -e .
+
+# If you want to run experiments using Ray, etc.:
 pip install -r requirements.txt
 pip install -e .[extras]
 ```
-This might be the preferred way if you want easy access to the included experiments.
 
 #### From PyPI
 Alternatively, MDP Playground can also be installed from PyPI. Just run:
 ```bash
+# If you just want to use the environments as in example.py:
+pip install mdp_playground
+
+# If you want to run experiments using Ray, etc.:
 pip install mdp_playground[extras]
 ```
 

setup.py

@@ -12,17 +12,17 @@
 package_data = {"": ["*"]}
 
 extras_require = [
-    "ray[default,rllib]==1.0.0",
-    "tensorflow==2.5.0",
+    "ray[default,rllib]>=1.0.0",
+    "tensorflow>=2.5.0",
     "pillow>=6.1.0",
-    "requests==2.22.0",
-    "configspace==0.4.10",
+    "requests>=2.22.0",
+    "configspace>=0.4.10",
     "scipy>=1.7.0",
     "pandas>=0.25.0",
-    "gym[atari]==0.20",
+    "gym[atari]<=0.25",
     "matplotlib",
-    "opencv-python==4.2.0.34",  # due to https://stackoverflow.com/questions/72706073/attributeerror-partially-initialized-module-cv2-has-no-attribute-gapi-wip-gs
-    "opencv-python-headless==4.2.0.34", # and https://stackoverflow.com/questions/70537488/cannot-import-name-registermattype-from-cv2-cv2
+    "opencv-python>=4.2.0.34",  # due to https://stackoverflow.com/questions/72706073/attributeerror-partially-initialized-module-cv2-has-no-attribute-gapi-wip-gs
+    "opencv-python-headless>=4.2.0.34", # and https://stackoverflow.com/questions/70537488/cannot-import-name-registermattype-from-cv2-cv2
 ]
 
 extras_require_disc = [