[requirements] have manage.py ensure requirements are up to date

src/manage.py

@@ -3,6 +3,7 @@
 
 import os
 import sys
+from pathlib import Path
 
 
 def main():
@@ -11,6 +12,19 @@ def main():
 
     from configurations.management import execute_from_command_line
 
+    try:
+        import pip_lock
+    except ModuleNotFoundError:
+        raise ModuleNotFoundError(
+            "Couldn't import pip-lock. Are you on the right virtualenv and up to date?"
+        )
+
+    requirements_path = str(Path(__file__).parent.parent / "requirements/base.txt")
+    pip_lock.check_requirements(
+        requirements_path,
+        post_text="\nRun the following:\n\npython -m pip install -r requirements/base.txt\n",
+    )
+
     execute_from_command_line(sys.argv)