making pickle compatible py 2 and 3

Author: oesteban

circle.yml

@@ -46,7 +46,7 @@ test:
     - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_fsl_reuse Linear /root/examples/ level1_workflow
     - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py27 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
     - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
-    - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested Linear /root/examples/ l2pipeline
+    - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ l2pipeline
 
   post:
     - bash docker/circleci/teardown.sh

nipype/utils/filemanip.py

@@ -475,11 +475,12 @@ def loadpkl(infile):
 
 
 def savepkl(filename, record):
+    content = pickle.dumps(record)
     if filename.endswith('pklz'):
         pkl_file = gzip.open(filename, 'wb')
     else:
         pkl_file = open(filename, 'wb')
-    pickle.dump(record, pkl_file)
+    pkl_file.write(content.encode())
     pkl_file.close()
 
 rst_levels = ['=', '-', '~', '+']