Bump version to 7.x

Author: rocky

pymathics/graph/version.py

@@ -5,4 +5,4 @@
 # well as importing into Python. That's why there is no
 # space around "=" below.
 # fmt: off
-__version__="6.1.0dev0"  # noqa
+__version__="7.0.0dev0"  # noqa

setup.py

@@ -32,7 +32,7 @@ def read(*rnames):
     version=__version__,  # noqa
     packages=find_namespace_packages(include=["pymathics.*"]),
     install_requires=[
-        "Mathics3>=6.0.0",
+        "Mathics3>=6.0.1",
         "networkx>=3.0.0",
         "pydot",
         "matplotlib",