Unit-test the connector helper functions

The cassettes cannot reach these branches. Every fixture email is
already lowercase, so nothing exercised the trim-and-lowercase that is
the Google Analytics driver's whole merge key; likewise the Dotfile role
casing and the Segment role dedup and case-insensitive owner match.

The Dotfile and Square tests never asserted CreatedAt, which
parseRFC3339Ptr silently nils on any format mismatch — both cassettes
carry usable timestamps, so a dropped field looked like a clean pass.

Also gives the Square OAuth variables their own comment in the example
env file; they sat under the Google Analytics one.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/accessreview/drivers/square_test.go

@@ -24,6 +24,7 @@ import (
 	"context"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -49,6 +50,10 @@ func TestSquareDriver(t *testing.T) {
 	assert.Equal(t, []string{"Member"}, member.Roles)
 	require.NotNil(t, member.Active)
 	assert.True(t, *member.Active)
+	// parseRFC3339Ptr nils on any format mismatch, so pin the parsed instant:
+	// a silently dropped created_at would otherwise look like a clean pass.
+	require.NotNil(t, member.CreatedAt)
+	assert.Equal(t, "2020-03-24T18:14:26Z", member.CreatedAt.UTC().Format(time.RFC3339))
 
 	// Owner → is_owner drives IsAdmin directly.
 	owner := records[1]