Fix version imports and versioningit setup.

Fix version and add test

Author: hmacdope

mtenn/__init__.py

@@ -1 +1,4 @@
 """Modular Training and Evaluation of Neural Networks"""
+
+from importlib.metadata import version
+__version__ = version("mtenn")

mtenn/_version.py

@@ -0,0 +1,4 @@
+import mtenn
+
+def test_version():
+    assert mtenn.__version__

mtenn/_version_git.py

@@ -33,11 +33,6 @@ dirty = "{base_version}+{distance}.{vcs}{rev}.dirty"
 distance-dirty = "{base_version}+{distance}.{vcs}{rev}.dirty"
 
 [tool.versioningit.vcs]
-# The method key:
-method = "git"  # <- The method name
-# Parameters to pass to the method:
+method = "git" 
 match = ["*"]
-default-tag = "0.0.0"
-
-[tool.versioningit.write]
-file = "mtenn/_version.py"
+default-tag = "0.0.0"