added isGeneric method and tests

checker.go

@@ -0,0 +1,30 @@
+package checker
+
+import (
+	"fmt"
+	"strings"
+)
+
+// IsValid preform a simple validation check to see if the email is correctly formatted.
+// An error is returned if not.
+func IsValid(email string) error {
+	return nil
+}
+
+// IsGeneric will check if the email address is provided by a free services provider.
+// As an example will return true if the email is provided by gmail.com
+func IsGeneric(email string) (bool, error) {
+	parts := strings.Split(email, "@")
+
+	if len(parts) <= 1 {
+		return false, fmt.Errorf("given an invalid email")
+	}
+
+	for _, d := range domains {
+		if d == parts[1] {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}