feat: handleAllTrackEvents is no longer used (#48)

* feat: use frontend-analytics directly

BREAKING CHANGE: handleAllTrackEvents is no longer part of the Footer props API.  The footer uses frontend-analytics’s sendTrackEvent directly.

Also updating other dependencies to keep them up to date.  This part should probably be a separate PR, technically.

* fix: remove unused dependency of frontend-logging

* fix: a little PR cleanup

* fix: putting frontend logging back

It’s needed by frontend-i18n and fails if it’s not there for tests.

* fix: pinning npm at 6

README.rst

@@ -22,7 +22,6 @@ Component Usage::
    ...
 
    <Footer
-      handleAllTrackEvents={(eventName, properties) => {/* track click event */}}
       onLanguageSelected={(languageCode) => {/* set language */}}
       supportedLanguages={[
          { label: 'English', value: 'en'},
@@ -30,7 +29,6 @@ Component Usage::
       ]}
    />
 
-- handleAllTrackEvents (required)
 - onLanguageSelected (optional)
 - supportedLanguages (optional)