update to work with tox 2.1.1

Author: dhellmann

tests/setup.sh

@@ -10,3 +10,8 @@ export WORKON_HOME=$(mktemp -d -t "WORKON_HOME.XXXX.$$")
 export PROJECT_HOME=$(mktemp -d -t "PROJECT_HOME.XXXX.$$")
 
 #unset HOOK_VERBOSE_OPTION
+
+# tox no longer exports these variables by default, so set them
+# ourselves to ensure the tests that rely on the values work
+export USER=$(id -u -n)
+export HOME=$(id -P | cut -f9 -d:)