Raise error if files passed on CLI do not exist

Prevents pyuploadtool from starting the deployment release and deleting old releases before noticing halfway that the files cannot be found.

Author: TheAssassin

pyuploadtool/__main__.py

@@ -2,6 +2,7 @@
 Commandline interface.
 """
 
+import os
 import sys
 
 
@@ -25,6 +26,11 @@
     sys.exit(1)
 
 
+for artifact in artifacts:
+    if not os.path.exists(artifact):
+        raise FileNotFoundError(artifact)
+
+
 def get_metadata():
     # create some metadata, which will be updated with the data from the build system
     logger.debug("creating empty metadata object")