Replace iconomist and favicon with responsive_favicons

[govcms]

Replace iconomist and favicon with responsive_favicons

[fiasco]

Seems like a good idea, can we get a pull request for it?

[aleayr]

As part of testing and merging this in, we need to consider how this will effect (and how we test) the change on existing sites.

[fiasco]

@aleayr agreed, but we need to do that with a pull request provided ;)

[fiasco]

@typhonius we're keen to see this in govCMS but we need some help:

1. we need to reroll the PR
2. we need instructions for how an agency can test this change

[typhonius]

I've addressed this in #247. An agency should undergo the following steps:

• Patch govCMS codebase to include change
• Run update
• Ensure favicon and iconomist modules are disabled, uninstalled and unable to be reinstalled
• Ensure that responsive_favicon module is enabled if favicon module was enabled prior.

[aleayr]

@Venkata-modgu Can we get this tested #247 for merging?

[aleayr]

Due to complexities in modifying existing customer sites, and depecating this, I'm closing.