tests: remove unused os package import

os package is imported by every test script but only used by a few, thus flake8 check reported errors.

tests: remove unused os package import
f9824abe · Sebastian Meiling · 13d61b5c · f9824abe · f9824abe · f9824abe
Commit f9824abe authored 6 years ago by Sebastian Meiling
--- a/tests/xtimer_now64_continuity/tests/01-run.py
+++ b/tests/xtimer_now64_continuity/tests/01-run.py
--- a/tests/xtimer_periodic_wakeup/tests/01-run.py
+++ b/tests/xtimer_periodic_wakeup/tests/01-run.py
--- a/tests/xtimer_remove/tests/01-run.py
+++ b/tests/xtimer_remove/tests/01-run.py
--- a/tests/xtimer_reset/tests/01-run.py
+++ b/tests/xtimer_reset/tests/01-run.py
--- a/tests/xtimer_usleep/tests/01-run.py
+++ b/tests/xtimer_usleep/tests/01-run.py
--- a/tests/xtimer_usleep_short/tests/01-run.py
+++ b/tests/xtimer_usleep_short/tests/01-run.py