tests/py-watch: replace subprocess.call with newer variant

As subprocess.call is replaced by subprocess.run if you need to capture
output. So let's use the new variant.

Signed-off-by: Jean-Louis Dupond <jean-louis@dupond.be>

Author: dupondje

tests/py-watch

@@ -37,9 +37,12 @@ def parse_args(argv):
 
 
 def dump_trace(proc):
-    subprocess.call([
+    out = subprocess.run([
         'gdb', '-p', str(proc.pid), '--batch', '-ex',
-        'thread apply all py-bt'])
+        'thread apply all py-bt'],
+        capture_output=True)
+    print(out.stdout)
+    print(out.stderr)
 
 
 def terminate(signo, frame):

tox.ini

@@ -51,7 +51,7 @@ setenv =
 deps = {[base]deps}
 changedir = {[base]changedir}
 commands =
-    python profile {envname} pytest -m {[base]markers} --durations=10 {posargs} \
+    python profile {envname} pytest -sv -m {[base]markers} --durations=10 {posargs} \
         --cov=vdsm \
         --cov=yajsonrpc \
         --cov-report=html:htmlcov-lib \