Automatically create a 'test-output' directory in the current directory if no

output path is specified. Test output files are placed in this directory.
Furthermore the filenames now have the prefix "test" (but otherwise are the
string representation of the spec ID as before).

lib/spack/spack/cmd/test-install.py

@@ -173,7 +173,10 @@ def test_install(parser, args):
     
     if not args.output:
         bId = BuildId(topSpec)
-        outputFpath = join_path(os.getcwd(), "{0}.xml".format(bId.stringId()))
+        outputDir = join_path(os.getcwd(), "test-output")
+        if not os.path.exists(outputDir):
+            os.mkdir(outputDir)
+        outputFpath = join_path(outputDir, "test-{0}.xml".format(bId.stringId()))
     else:
         outputFpath = args.output