Fix pre-prompt ccds version error (#426)

* fix pre-prompt ccds version error by moving versioning into __init__ and removing any module-level imports from pre-prompt

* wrap pre_prompt import of ccds version in try/except

* use more specific try/except for import error handling to yield the desired behavior

Author: chrisjkuch

ccds/__init__.py

@@ -1,3 +1,3 @@
-from ccds.version import __version__
+from importlib.metadata import version
 
-__version__
+__version__ = version("cookiecutter-data-science")

ccds/__main__.py

@@ -23,7 +23,7 @@
 from cookiecutter import cli
 from cookiecutter import main as api_main  # noqa: F401 referenced by tests
 
-from ccds.version import __version__
+from ccds import __version__
 
 
 def default_ccds_main(f):

ccds/version.py

@@ -0,0 +1,18 @@
+import warnings
+
+try:
+    from ccds import __version__
+except ModuleNotFoundError:
+    __version__ = None  # ccds is not installed
+except ImportError:
+    __version__ = "2.0.0"  # ccds is installed but version is 2.0.0
+
+if __name__ == "__main__":
+    if __version__ is not None and __version__ < "2.0.1":
+        warnings.warn(
+            "You're currently using a CCDS version that always applies the "
+            "newest template. For more stable behavior, upgrade to "
+            "CCDS version 2.0.1 or later with your package manager. "
+            "For example, with pip, run: pip install -U cookiecutter-data-science.",
+            DeprecationWarning,
+        )