Fixed issue with is_snake_case regex

Author: rbob86

linter/helpers.py

@@ -18,5 +18,5 @@ def pascal_case_to_snake_case(pascal_case: str) -> str:
 
 
 def is_snake_case(name: str) -> bool:
-    pattern = compile(r'^[a-z][a-z0-9]+(_[a-z0-9]+)*$')
+    pattern = compile(r'^[a-z0-9]+(_[a-z0-9]+)*$')
     return pattern.match(name) is not None

test/rules/test_field_name_is_snake_case.py

@@ -6,7 +6,7 @@ def test_run_method_successfully_validates_field_name_is_snake_case() -> None:
     rule = FieldNameIsSnakeCase(Severity.ERROR.value)
 
     field = {
-        'name': 'order_id',
+        'name': 't_order_id',
         'primary_key': 'yes',
         'sql': '${TABLE}.ORDER_ID',
         'type': 'number',