Add DISABLE_STRICT_COVERAGE to modules which need it (round #2)

For some reason some of these issues were only detected on
recipe autoroller bot.

TBR=iannucci

BUG=693058

Change-Id: I5d4a1243850a31d5430f2dc07be4a5138551ef82
Reviewed-on: https://chromium-review.googlesource.com/444884Reviewed-by: Paweł Hajdan Jr. <phajdan.jr@chromium.org>
Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>

recipe_modules/infra_paths/__init__.py

@@ -2,3 +2,6 @@ DEPS = [
   'recipe_engine/path',
   'recipe_engine/properties',
 ]
+
+# TODO(phajdan): provide coverage (http://crbug.com/693058).
+DISABLE_STRICT_COVERAGE = True

recipe_modules/tryserver/__init__.py

@@ -14,3 +14,7 @@ DEPS = [
   'rietveld',
   'recipe_engine/step',
 ]
+
+
+# TODO(phajdan): provide coverage (http://crbug.com/693058).
+DISABLE_STRICT_COVERAGE = True