enable pedantic lints (dart-lang/stream_transform#61)

pkgs/stream_transform/analysis_options.yaml

diff --git a/pkgs/stream_transform/analysis_options.yaml b/pkgs/stream_transform/analysis_options.yaml
index dcfc239..6552885 100644
--- a/pkgs/stream_transform/analysis_options.yaml
+++ b/pkgs/stream_transform/analysis_options.yaml
@@ -1,3 +1,4 @@
+include: package:pedantic/analysis_options.yaml
 analyzer:
   strong-mode:
     implicit-casts: false
@@ -39,7 +40,6 @@
     - recursive_getters
     - slash_for_doc_comments
     - test_types_in_equals
-    - test_types_in_equals
     - throw_in_finally
     - type_init_formals
     - unrelated_type_equality_checks

pkgs/stream_transform/pubspec.yaml

diff --git a/pkgs/stream_transform/pubspec.yaml b/pkgs/stream_transform/pubspec.yaml
index a29a467..722cecd 100644
--- a/pkgs/stream_transform/pubspec.yaml
+++ b/pkgs/stream_transform/pubspec.yaml
@@ -8,4 +8,5 @@
   sdk: ">=2.1.0 <3.0.0"
 
 dev_dependencies:
+  pedantic: ^1.5.0
   test: ^1.0.0