Download sale records
Eliminated offensive words from registration code generation.
changed the wording on the receipt page
added the email address in the redeemed_by coulmn
Merge pull request #4851 from edx/asadiqbal08/download_sales_records

(WIP) Download sale records
Merge pull request #4852 from edx/asadiqbal08/avoid_to_produce_offensive_codes

(WIP) Eliminated offensive words from registration code generation.
Merge pull request #4861 from edx/muhhshoaib/Ex-65-change-wording-on-receipt-page

changed the wording on the receipt page
Merge pull request #4862 from edx/muhhshoaib/Ex-64-redeemed_by-in-the-registration-codes-should-be-an-email-address

added the email address in the redeemed_by coulmn
downloaded all historical coupon codes

rebased and resolved conflicts