[tests] Generate a temporary test prefix

This will rsync prefixes of all needed packages in one place in
order to provide a single prefix like on development or production
setup.

This will allow the removal of the use of the Prefix class that was
mainly use only in tests.

beat/cmdline/test/__init__.py

@@ -28,10 +28,15 @@
 # Basic setup for command test
 
 import os
+import sys
+import tempfile
+import shutil
+import subprocess
+import pkg_resources
 
 import six.moves.urllib as urllib
 
-from beat.core.test import prefix, tmp_prefix, teardown_package
+from beat.core.test import tmp_prefix, teardown_package
 
 platform = os.environ.get('BEAT_CMDLINE_TEST_PLATFORM', '')
 
@@ -65,3 +70,29 @@ else:
 
 user = 'user'
 token = '4'
+
+
+if sys.platform == 'darwin':
+    tmp_folder = tempfile.mkdtemp(prefix=__name__, suffix='.tmpdir', dir='/tmp')
+else:
+    tmp_folder = tempfile.mkdtemp(prefix=__name__, suffix='.tmpdir')
+
+prefix = os.path.join(tmp_folder, 'prefix')
+
+
+def rsync_to_tmp(path):
+  subprocess.check_call(['rsync', '-arz', path, tmp_folder])
+
+
+def setup_package():
+  prefixes = [
+    pkg_resources.resource_filename('beat.backend.python.test', 'prefix'),
+    pkg_resources.resource_filename('beat.core.test', 'prefix')
+  ]
+
+  for path in prefixes:
+    rsync_to_tmp(path)
+
+
+def teardown_package():
+  shutil.rmtree(tmp_folder)