force python 3 in setup

Author: azoner

.github/workflows/main.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9]
+        python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
       - uses: actions/checkout@v2

setup.py

@@ -11,7 +11,8 @@
 
 setup(
     name="pyx12",
-    version="3.0.0rc1",
+    python_requires='>=3.6',
+    version="3.0.0rc2",
     long_description=LONG_DESCRIPTION,
     license='BSD',
     description="HIPAA X12 validator, parser and converter",