Merge branch 'hotfix_workaround_toil' into 'master'

Implemented workaround for toil issue 4930

See merge request !57

steps/aoflagger.cwl

@@ -35,7 +35,7 @@ inputs:
       doc: Indicates whether statistics should be written to file.
 
     - id: linc_libraries
-      type: File[]
+      type: File[]? # This is optional as a workaround for toil, see https://github.com/DataBiosphere/toil/issues/4930
       doc: |
         Scripts and reference files from the
         LOFAR INitial calibration pipeline.
@@ -53,8 +53,8 @@ inputs:
 
     - id: memory
       type: 
-        - int
-        - float
+        - int?
+        - float? # These are optional as a workaround for toil, see https://github.com/DataBiosphere/toil/issues/4930
       inputBinding:
         position: 0
         prefix: aoflagger.memorymax=

steps/dp3_applycal_ddf.cwl

@@ -18,7 +18,7 @@ arguments:
 
 inputs:
     - id: msin
-      type: Directory
+      type: Directory? # This is optional as a workaround for toil, see https://github.com/DataBiosphere/toil/issues/4930
       doc: Input data in MeasurementSet format.
       inputBinding:
         position: 0
@@ -26,7 +26,7 @@ inputs:
         separate: false
 
     - id: ddf_solset
-      type: File
+      type: File? # This is optional as a workaround for toil, see https://github.com/DataBiosphere/toil/issues/4930
       doc: |
         The solution tables generated by
         the DDF pipeline in an HDF5 format.