[minor] don't rollback when running all tests, fixed test cases

accounts/doctype/period_closing_voucher/test_period_closing_voucher.py

@@ -8,6 +8,9 @@ import webnotes
 
 class TestPeriodClosingVoucher(unittest.TestCase):
 	def test_closing_entry(self):
+		# clear GL Entries
+		webnotes.conn.sql("""delete from `tabGL Entry`""")
+		
 		from accounts.doctype.journal_voucher.test_journal_voucher import test_records as jv_records
 		jv = webnotes.bean(copy=jv_records[2])
 		jv.insert()

accounts/doctype/purchase_invoice/purchase_invoice.py

@@ -434,7 +434,7 @@ class DocType(BuyingController):
 	def update_raw_material_cost(self):
 		if self.sub_contracted_items:
 			for d in self.doclist.get({"parentfield": "entries"}):
-				rm_cost = webnotes.conn.sql(""" select raw_material_cost / quantity 
+				rm_cost = webnotes.conn.sql("""select raw_material_cost / quantity 
 					from `tabBOM` where item = %s and is_default = 1 and docstatus = 1 
 					and is_active = 1 """, (d.item_code,))
 				rm_cost = rm_cost and flt(rm_cost[0][0]) or 0