remote_access: convert to python3 only

All users of these modules are python3 only already.

BUG=chromium:997354
TEST=`./run_tests` passes

Change-Id: I03275891886b381b3520a0610d9d2a3381636409
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2644817
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/lib/remote_access.py b/lib/remote_access.py
index 088a18f..f8461f0 100644
--- a/lib/remote_access.py
+++ b/lib/remote_access.py
@@ -14,6 +14,7 @@
 import socket
 import stat
 import subprocess
+import sys
 import tempfile
 import time
 
@@ -29,6 +30,9 @@
 from chromite.utils import memoize
 
 
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 _path = os.path.dirname(os.path.realpath(__file__))
 TEST_PRIVATE_KEY = os.path.normpath(
     os.path.join(_path, '../ssh_keys/testing_rsa'))
diff --git a/lib/remote_access_unittest b/lib/remote_access_unittest
deleted file mode 120000
index 72196ce..0000000
--- a/lib/remote_access_unittest
+++ /dev/null
@@ -1 +0,0 @@
-../scripts/wrapper.py
\ No newline at end of file
diff --git a/lib/remote_access_unittest.py b/lib/remote_access_unittest.py
index 6ed3867..9e842d2 100644
--- a/lib/remote_access_unittest.py
+++ b/lib/remote_access_unittest.py
@@ -8,6 +8,7 @@
 from __future__ import print_function
 
 import os
+import sys
 
 from chromite.lib import cros_build_lib
 from chromite.lib import cros_test_lib
@@ -16,6 +17,9 @@
 from chromite.lib import remote_access
 
 
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 # pylint: disable=protected-access