Need for Basic sanity check for yaml files in Travis CI

[AYUSHJAIN951]

With in Travis CI can there be a way to do have a basic sanity check for yaml's?
Like use of "=" should be catched initially itself and asked to update to ":", and other basic checks could be incorporated as well.

For eg in #2654 we can see there is issue with yaml which went in without a check and causes issues like below later.

avocado run --max-parallel-tasks 1 memhotplug.py -m memhotplug.py.data/memhotplug.yaml
JOB HTML : /home/AvocadoTests_src/results/job-2023-10-11T05.23-3e7f92e/results.html
JOB TIME : 434.15 s
JOB ID : a7793f2978f3fa74b9b234b1d51f34f4f43375d6
JOB LOG : /home/AvocadoTests_src/results/job-2023-10-11T05.36-a7793f2/job.log
(1/4) memhotplug.py:MemStress.test_hotplug_loop;run-fb7c: STARTED
Invalid multiplex file 'memhotplug.py.data/memhotplug.yaml': mapping values are not allowed in this context
in "memhotplug.py.data/memhotplug.yaml", line 2, column 10
Make sure !tags and colons are separated by a space (eg. !include :) : memhotplug.py.data/memhotplug.yaml

[AYUSHJAIN951]

@PraveenPenguin @Naresh-ibm @narasimhan-v

[AYUSHJAIN951]

Related PR #2718