Ensure email is unique

Ideally we'd be able to ask Faker for a unique value
but handling on our end until that feature is available:

dmgk/faker#12

etc/magento2.yml

@@ -5,19 +5,19 @@ tables:
     columns:
       firstname: firstname
       lastname: lastname
-      email: email
+      email: unique_email
       username: username
       password: password
   - name: customer_entity
     columns:
-      email: email
+      email: unique_email
       firstname: firstname
       lastname: lastname
       vat_id: vat_number
   - name: customer_grid_flat
     columns:
       name: fullname
-      email: email
+      email: unique_email
       dob: date
       gender: gender
       taxvat: vat_number
@@ -47,11 +47,11 @@ tables:
       vat_id: vat_number
   - name: newsletter_subscriber
     columns:
-      subscriber_email: email
+      subscriber_email: unique_email
       subscriber_confirm_code: md5
   - name: quote
     columns:
-      customer_email: email
+      customer_email: unique_email
       customer_prefix: title
       customer_firstname: firstname
       customer_middlename: firstname
@@ -62,7 +62,7 @@ tables:
       remote_ip: ipv4
   - name: quote_address
     columns:
-      email: email
+      email: unique_email
       prefix: title
       firstname: firstname
       lastname: lastname
@@ -89,18 +89,18 @@ tables:
       billing_address: street
       shipping_address: street
       customer_name: fullname
-      customer_email: email
+      customer_email: unique_email
   - name: sales_invoice_grid
     columns:
       customer_name: fullname
-      customer_email: email
+      customer_email: unique_email
       billing_name: fullname
       billing_address: street
       shipping_address: street
   - name: sales_order
     columns:
       customer_dob: datetime
-      customer_email: email
+      customer_email: unique_email
       customer_prefix: title
       customer_firstname: firstname
       customer_middlename: firstname
@@ -115,7 +115,7 @@ tables:
       lastname: lastname
       street: street
       city: city
-      email: email
+      email: unique_email
       telephone: telephone
       firstname: firstname
       prefix: title
@@ -128,7 +128,7 @@ tables:
       billing_name: fullname
       billing_address: street
       shipping_address: street
-      customer_email: email
+      customer_email: unique_email
       cutomer_name: fullname
   - name: sales_shipment_grid
     columns:
@@ -137,14 +137,14 @@ tables:
       shipping_address: street
       billing_name: fullname
       shipping_name: fullname
-      customer_email: email
+      customer_email: unique_email
   - name: sendfriend_log
     columns:
       ip: ipv4
 eav:
   - name: customer
     attributes:
-      email: email
+      email: unique_email
       prefix: title
       firstname: firstname
       middlename: firstname

src/provider.go

@@ -1,13 +1,19 @@
 package dbanon
 
 import (
+	"strconv"
+	"strings"
 	"syreclabs.com/go/faker"
 )
 
-type Provider struct{}
+type Provider struct{
+	providedUniqueEmails map[string]int
+}
 
 func NewProvider() *Provider {
-	p := &Provider{}
+	made := make(map[string]int)
+
+	p := &Provider{providedUniqueEmails: made}
 
 	return p
 }
@@ -26,6 +32,19 @@ func (p Provider) Get(s string) string {
 		return faker.Name().FirstName() + " " + faker.Name().LastName()
 	case "email":
 		return faker.Internet().Email()
+	case "unique_email":
+		new := faker.Internet().Email()
+
+		_, exists := p.providedUniqueEmails[new]
+		if !exists {
+			p.providedUniqueEmails[new] = 0
+			return new
+		}
+
+		p.providedUniqueEmails[new]++
+		ret := strings.Join([]string{strconv.Itoa(p.providedUniqueEmails[new]), new}, "")
+
+		return ret
 	case "username":
 		return faker.Internet().UserName()
 	case "password":