Incomplete test description for scaling tests.

[marcemq]

From code we currently have four type of scaling tests:

• k8s_parallel.sh
• k8s_scale_nc.sh
• k8s_scale_rapid.sh
• k8s_scale.sh

which have the same description for all tests when asking for test execution help:

$ ./k8s_scale.sh -h
Usage: ./scaling/k8s_scale.sh [-h] [options]
   Description:
        Launch a series of workloads and take memory metric measurements after
        each launch.
   Options:
                -h,    Help page.

Environment variables:
        Name (default)
                Description
        TEST_NAME (k8s scaling)
                Can be set to over-ride the default JSON results filename
        NUM_PODS (20)
                Number of pods to launch
        STEP (1)
                Number of pods to launch per cycle
        wait_time (30)
                Seconds to wait for pods to become ready
        delete_wait_time (600)
                Seconds to wait for all pods to be deleted
        settle_time (5)
                Seconds to wait after pods ready before taking measurements
        use_api (yes)
                specify yes or no to use the API to launch pods
        grace (30)
                specify the grace period in seconds for workload pod termination

such description is incomplete and it can lead to a confusion, they exist because they're different which needs to be reflect on each test description and the README file.

[marcemq]

The PR #262 edits the description of k8s_parallel.sh and k8s_scale.sh, so we're half way to close this issue.

[marcemq]

The PR #278 edits the description of k8s_scale_rapid.sh and k8s_scale_nc.sh, once such changes get accepted we can closed this issue.