Update ClaySelect Markup

[matuzalemsteles]

The class .form-inline-group was renamed to .form-group-item in v2.0.0-beta.5 December 25, 2017. Hey @pat270 let me know if I'm wrong about this.

I do not know if it does but feel we have the wrapperType API, maybe we can just go with an inline to true to add the .form-group-item class. This way it does not risk breaking an API when a markup change and does not depend on the API input.

Current

class="
	{if $wrapperType}
		form-{$wrapperType}
	{else}
		form-group
	{/if}

	{if $elementClasses}
		{sp}{$elementClasses}
	{/if}
"

New

class="
	{if $inline}
		form-group-item
	{else}
		form-group
	{/if}

	{if $elementClasses}
		{sp}{$elementClasses}
	{/if}
"

I do not know if it's the best time to change the API. What do you think? @carloslancha