Currency filter in Pricing Rule (#11776)

* added currency filter

* modified files

* pull margin only if currency matches

* Renamed price to rate in pricing rule

* fetch rate only if currency matches

* rebase with develop

* rebase with develop

* patch to set currency in existing docs

* currency field mandatory in pricing rule

* modified test cases

* rebase with develop

* fixed test case
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 8f9a392..243158c 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -494,6 +494,8 @@
 erpnext.patches.v10_0.update_sales_order_link_to_purchase_order
 erpnext.patches.v10_0.added_extra_gst_custom_field_in_gstr2 #2018-02-13
 erpnext.patches.v10_0.item_barcode_childtable_migrate
+erpnext.patches.v10_0.rename_price_to_rate_in_pricing_rule
+erpnext.patches.v10_0.set_currency_in_pricing_rule
 erpnext.patches.v10_0.workflow_expense_claim
 erpnext.patches.v10_0.set_b2c_limit
 erpnext.patches.v10_0.update_translatable_fields