Don't include README in docker

Dockerfile

@@ -37,7 +37,6 @@ RUN pip3 install -r /pysr/requirements.txt
 # Install PySR:
 # We do a minimal copy so it doesn't need to rerun at every file change:
 ADD ./setup.py /pysr/setup.py
-ADD ./README.md /pysr/README.md
 ADD ./pysr/ /pysr/pysr/
 RUN pip3 install .
 

setup.py

@@ -1,7 +1,10 @@
 import setuptools
 
-with open("README.md", "r") as fh:
-    long_description = fh.read()
+try:
+    with open("README.md", "r") as fh:
+        long_description = fh.read()
+except FileNotFoundError:
+    long_description = ""
 
 setuptools.setup(
     name="pysr",