Merge pull request #326 from JuliaRobotics/hotfix/1Q20/318

re-add keyword in saveDFG with deprecation

Author: dehann

src/FileDFG/services/FileDFG.jl

@@ -3,6 +3,9 @@
     $(SIGNATURES)
 Save a DFG to a folder. Will create/overwrite folder if it exists.
 
+DevNotes:
+- TODO remove `compress` kwarg.
+
 # Example
 ```julia
 using DistributedFactorGraphs, IncrementalInference
@@ -14,8 +17,12 @@ v1 = addVariable!(dfg, :a, ContinuousScalar, labels = [:POSE], solvable=0)
 saveDFG(dfg, "/tmp/saveDFG.tar.gz")
 ```
 """
-function saveDFG(dfg::AbstractDFG, folder::String)
+function saveDFG(dfg::AbstractDFG, folder::String; compress::Symbol=:null)
 
+    if compress != :null
+      @warn "saveDFG keyword args are deprecated, and folders will be tarred as standard in current and future versions."
+    end
+        
     # TODO: Deprecate the folder functionality in v0.6.1
 
     # Clean up save path if a file is specified