Don't use hardcoded paths in test

(cherry-picked from 8b04188)

Author: nyalldawson

python/plugins/processing/tests/Grass7AlgorithmsVectorTest.py

@@ -30,6 +30,7 @@
 import nose2
 import shutil
 import os
+import tempfile
 
 from qgis.core import (QgsVectorLayer,
                        QgsApplication,
@@ -56,6 +57,9 @@ def setUpClass(cls):
         Processing.initialize()
         cls.cleanup_paths = []
 
+        cls.temp_dir = tempfile.mkdtemp()
+        cls.cleanup_paths.append(cls.temp_dir)
+
         assert Grass7Utils.installedVersion()
 
     @classmethod
@@ -88,7 +92,8 @@ def testMemoryLayerInput(self):
 
         alg = QgsApplication.processingRegistry().createAlgorithmById('grass7:v.buffer')
         self.assertIsNotNone(alg)
-        temp_file = '/tmp/grass_output.shp'
+
+        temp_file = os.path.join(self.temp_dir,'grass_output.shp')
         parameters ={'input':'testmem',
                      'type':[0,1,4],
                      'distance':1,
@@ -138,7 +143,7 @@ def testFeatureSourceInput(self):
 
         alg = QgsApplication.processingRegistry().createAlgorithmById('grass7:v.buffer')
         self.assertIsNotNone(alg)
-        temp_file = '/tmp/grass_output.shp'
+        temp_file = os.path.join(self.temp_dir,'grass_output_sel.shp')
         parameters = {'input': QgsProcessingFeatureSourceDefinition('testmem', True),
                       'type': [0, 1, 4],
                       'distance': 1,