Merged in NRRPLT-8524-fix-vulnerabilities (pull request #147)

[NRRPLT-8524] Fix known vulnerabilities

* [NRRPLT-8524] fix PyYAML==5.4
https://github.com/advisories/GHSA-8q59-q68h-6hv4
* [NRRPLT-8524] fix lxml==4.6.5
https://github.com/advisories/GHSA-55x5-fj6c-h6m8
* [NRRPLT-8524] fix psutil==5.6.6
https://github.com/advisories/GHSA-qfc5-mcwq-26q8
* [NRRPLT-8524] Pin urllib3[secure]==1.26.5
https://github.com/advisories/GHSA-q2q7-5pp4-w6pg

Approved-by: Ugo Albanese
Approved-by: Eloy Retamino

hbp_nrp_backend/requirements.txt

 hbp-nrp-commons
 # other requirements
-lxml==4.5.2
-PyYAML==5.3.1
+lxml==4.6.5
+PyYAML==5.4
 rospkg==1.2.10
 catkin_pkg==0.4.23
 pyxb==1.2.6
@@ -9,7 +9,7 @@ Flask-Script==2.0.5
 Flask-Migrate==1.6.0
 psycopg2==2.8.6
 timeout-decorator==0.4.1
-urllib3[secure]==1.25.11
+urllib3[secure]==1.26.5
 ptvsd==4.3.2
 requests
 cryptography>=2.8

hbp_nrp_commons/requirements.txt

 pyxb==1.2.6
 transitions==0.4.1
-PyYAML==5.3.1
+PyYAML==5.4
 rospkg==1.2.10
 catkin_pkg==0.4.23
 pexpect==4.8

hbp_nrp_watchdog/requirements.txt

-psutil==2.0.0
-PyYAML==5.3.1
+psutil==5.6.6
+PyYAML==5.4
 rospkg==1.2.10
 catkin_pkg==0.4.23
 future