fixed UI test failures
Skipping `Proxy` tests via CLI.

We're seeing issues with our CLI tests for creating proxies, which
initially were being caused by the fact that we were trying to check the
length of a file handler object to see if there were any errors. I have
updated the method where this issue was happening as well as tried to
document it as much as I could.

Currently, the process of creating an 'ssh tunnel' locks `Paramiko` and
prevents the test from completing, so I have skipped all existing tests
accordingly.
Merge pull request #1293 from tkolhar/test_cli

Added test for role create, and role permissions
Merge pull request #1299 from omaciel/fix-proxy-generator

Skipping `Proxy` tests via CLI.
Merge pull request #1295 from sghai/fixes

fixed UI test failures
test to upload rpm content to an existing repo
Merge pull request #1296 from sghai/upload-repo-content

test to upload rpm content to an existing repo
Do not check content-type of HTTP 204 messages

This fixes an error in commit 5b2277272dbb489eda5186e0853f7529d621c359.
Merge pull request #1303 from Ichimonji10/jenkins

Do not check content-type of HTTP 204 messages
Add and refactor API tests for products

Make `Product` inherit from `EntityReadMixin`. use this mixin to trim down
module `tests.foreman.api.test_product_v2`.

Test the ability to CRUD products by adding `Product` to module
`test_multiple_paths.py`. Remove a deletion-related test from module
`test_product_v2` because `test_multiple_paths` covers the same ground.
Refactor and better test Repository.path

Refactor method `Repository.path` by trimming down the amount of underlying
code. Better test the method: only one of the two paths was being tested.
Merge pull request #1304 from Ichimonji10/test-product

Add and refactor API tests for products
Merge pull request #1307 from Ichimonji10/repository-path

Refactor and better test Repository.path
Add API tests for config templates

Update the `ConfigTemplate` class definition: add mixins for creation, reading
and deletion. Thoroughly test the relevant API endpoints.
Merge pull request #1301 from Ichimonji10/test-config-template

Add API tests for config templates
Test API for template kinds

Test whether it is possible to issue an HTTP GET request to
`api/v2/template_kinds`.
Merge pull request #1306 from Ichimonji10/test-templatekind

Test API for template kinds
Fix typo in CLI proxy module

An exception was defined using def instead of class statement, fixing
this.

Also do some formatting adjustments like using single quote for string
in the entire module and some spell fixes.
Merge pull request #1308 from elyezer/cli-proxy

Fix typo in CLI proxy module
Updated docstrings and addressed review comments in pr 1295