Use mixed-case column names for all columns

integration_tests/data/sql/data_unpivot_quote.csv

@@ -1,4 +1,4 @@
-customer_id,created_at,sTaTuS,SEGMENT,name
+Customer_Id,Created_At,sTaTuS,SEGMENT,Name
 123,2017-01-01,active,tier 1,name 1
 234,2017-02-01,active,tier 3,name 3
 567,2017-03-01,churned,tier 2,name 2

integration_tests/data/sql/data_unpivot_quote_expected.csv

@@ -1,4 +1,4 @@
-customer_id,created_at,prop,val
+Customer_Id,Created_At,Prop,Val
 123,"2017-01-01","SEGMENT","tier 1"
 123,"2017-01-01","sTaTuS","active"
 234,"2017-02-01","SEGMENT","tier 3"

integration_tests/models/sql/test_unpivot_quote.sql

@@ -2,9 +2,9 @@
     {{ dbt_utils.unpivot(
         relation=ref('data_unpivot_quote'),
         cast_to=type_string(),
-        exclude=['customer_id', 'created_at'],
-        remove=['name'],
-        field_name='prop',
-        value_name='val',
+        exclude=['Customer_Id', 'Created_At'],
+        remove=['Name'],
+        field_name='Prop',
+        value_name='Val',
         quote_identifiers=True,
     ) }}