Merge pull request #1347 from fishtown-analytics/fix/warn-error-flag

re-add --warn-error flag

core/dbt/main.py

@@ -687,6 +687,14 @@ def parse_args(args):
  help='''Run schema validations at runtime. This will surface
  bugs in dbt, but may incur a performance penalty.''')
 
+ p.add_argument(
+ '--warn-error',
+ action='store_true',
+ help='''If dbt would normally warn, instead raise an exception.
+ Examples include --models that selects nothing, deprecations,
+ configurations with no associated models, invalid test configurations,
+ and missing sources/refs in tests''')
+
  # if set, run dbt in single-threaded mode: thread count is ignored, and
  # calls go through `map` instead of the thread pool. This is useful for
  # getting performance information about aspects of dbt that normally run in