adding option to turn off colors in the console

It would be awesome to turn off colored output in some environments.

We are stuck using Jenkins at work and it's probably incorrectly configured, but I don't have access to fix it's configuration.

The problem is this is what the logs look like:

```
Initialized cnt-feature-modal module, please edit ./client/init.js and ./client/cnt-feature-modal.js to match your feature
passed: [32mcan insert a new image[39m
starting [37mcan fetch next slideshow[39m
Initialized cnt-feature-modal module, please edit ./client/init.js and ./client/cnt-feature-modal.js to match your feature
passed: [32mcan fetch next slideshow[39m
starting [37mstitching new slide from next gallery[39m
Initialized cnt-feature-modal module, please edit ./client/init.js and ./client/cnt-feature-modal.js to match your feature
passed: [32mstitching new slide from next gallery[39m
starting [37mfind index of a slide in the DOM[39m
Initialized cnt-feature-modal module, please edit ./client/init.js and ./client/cnt-feature-modal.js to match your feature
passed: [32mfind index of a slide in the DOM[39m
[31mError: timeout of 2000ms exceeded[39m
[90m    {anonymous}() http://localhost:45091/__zuul/client.js:1075[39m
[90m    {anonymous}() http://localhost:45091/__zuul/client.js:688[39m
[90m    {anonymous}() http://localhost:45091/__zuul/framework.js:583[39m
[90m    {anonymous}() http://localhost:45091/__zuul/framework.js:4539[39m
[90m    {anonymous}() http://localhost:45091/__zuul/framework.js:4795[39m
[90m    done http://localhost:45091/__zuul/framework.js:4295[39m
[90m    {anonymous}() http://localhost:45091/__zuul/framework.js:4275[39m
```

Yeah, that's super ugly right?

I couldn't think of a good way to test this -- open to suggestions and happy to implement if necessary.