chore(package): update Enzyme

[layershifter]

Cut from #1459.

Problem

ThemeProvider was part of produced tree by Enzyme, it means that we should always should to call .find() method to get actual Button component. Also, with fela upgrade ThemeProvider become stateless component and it was impossible to use .state() method of Enzyme anymore.

Solution

Use wrappingComponent component option of shallow/mount that was introduced in new versions of Enzyme.

https://github.com/airbnb/enzyme/blob/master/docs/api/shallow.md#shallownode-options--shallowwrapper

Before update

    <ThemeProvider theme={{...}} overwrite={false}>
      <Button disabled={true} onClick={[Function: mockConstructor]} as="button" accessibility={[Function: buttonB
ehavior]}>
        <button className="ui-button" disabled={true} onClick={[Function]} onFocus={[Function]} role={[undefined]
} aria-disabled={true} />
      </Button>
    </ThemeProvider>

After update

    <Button disabled={true} onClick={[Function: mockConstructor]} as="button" accessibility={[Function: buttonBeh
avior]}>
      <button className="ui-button" disabled={true} onClick={[Function]} onFocus={[Function]} role={[undefined]}
aria-disabled={true} />
    </Button>

[layershifter]

• ThemeProvider is not needed anymore as we use wrappingComponent
• FelaTheme is not needed because we use ThemeContext directly perf(renderComponent): drop FelaTheme and use React.Context directly #1163

[layershifter]

This update also eliminates this craziness: previously we should update whole tree...

[layershifter]

This stuff was removed to make tests more clear

[DustyTheBot]

	Warnings
⚠️	There are no updates provided to CHANGELOG. Ensure there are no publicly visible changes introduced by this PR.

Generated by 🚫 dangerJS

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@6487506). Click here to learn what that means.
The diff coverage is 90.9%.

@@            Coverage Diff            @@
##             master    #1469   +/-   ##
=========================================
  Coverage          ?   73.45%           
=========================================
  Files             ?      806           
  Lines             ?     6088           
  Branches          ?     1798           
=========================================
  Hits              ?     4472           
  Misses            ?     1610           
  Partials          ?        6

Impacted Files	Coverage Δ
.../specs/commonTests/htmlIsAccessibilityCompliant.ts	100% <100%> (ø)
packages/react/test/utils/withProvider.tsx	100% <100%> (ø)
...ages/react/test/specs/commonTests/isConformant.tsx	92.41% <85.71%> (ø)

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[layershifter]

We don't need this because ThemeProvider is now outside the tree