Return non zero code on failure

src/nextflow_file.py

@@ -24,7 +24,7 @@ class Nextflow_File(Nextflow_Building_Blocks):
     def __init__(self, address, duplicate = True, DSL="", author = None, name = None, origin=None, output_dir='./results', display_info = True):
         self.file = address 
         print(self.get_file_address())
-        if(self.get_file_address().find('/')!=-1):
+        if(self.get_file_address().find('/')==-1):
             raise BioFlowInsightError(f"BioFlow-Insight cannot directly analyse a workflow from its directory. Please analyse the workflow from the parent directory instead.", num = -1)
         
         self.output_dir = Path(output_dir)