Improve parsing of browser desired capabilities

Improve parsing of browser desired capabilities:

• Can parse both .py and .json files
• Can handle nested options

More info: SeleniumBase/examples/capabilities/ReadMe.md

Sample cap file 1: (Generated from https://www.browserstack.com/automate/capabilities)

desired_cap = {
    'os': 'OS X',
    'os_version': 'High Sierra',
    'browser': 'Chrome',
    'browser_version': '77.0',
    'browserstack.local': 'false',
    'browserstack.selenium_version': '3.141.59'
}

Sample cap file 2: (Generated from https://wiki.saucelabs.com/display/DOCS/Platform+Configurator#/)

capabilities = {
    'browserName': 'firefox',
    'browserVersion': '70.0',
    'platformName': 'macOS 10.13',
    'sauce:options': {
    }
}

Optimize virtual display logging and the boilerplate

Optimize virtual display logging and update boilerplate:

• Optimize virtual display and logging code
• Update default logging level for WebDriver connections
• Add save_teardown_screenshot() and refactor BaseCase
• Update boilerplate to save a screenshot before the tearDown()
• Update a console script that creates a boilerplate

JS Optimization and Refactoring

JS Optimization and Refactoring

• Optimize JS by putting html <script> tags before the end of
• Refactor jQuery exception code
• Update logging around making web drivers executable

Update Firefox settings, reqs, examples, and docs

Update Firefox settings, dependencies, examples, and docs

• Improve Firefox compatibility by changing some default settings
• Update coverage and beautifulsoup4 requirements
• Add a test demonstrating the set_attribute() and set_attributes() methods
• Update the docs

tqdm dependency update

tqdm dependency update

• Update tqdm to >= 4.41.0

Update pytest and pytest-xdist versions

Update pytest and pytest-xdist versions

Update colorama version (Use colorama==0.4.3)

Update colorama version:

• Use colorama==0.4.3

Bump pytest to minimum version 5.3.2 (Python 3)

Bump pytest version:

• Bump pytest to minimum version 5.3.2 (Python 3)

Update Chrome options when running remotely

Update Chrome options when running remotely (and more)

• Update Chrome options to fix #445
• Also some other small updates

Refactor default browser sizes into a settings file

Settings refactoring

• Refactor default browser resolutions into a settings file
• Bump tqdm version to >=4.40.2