Add path back to pubspec. Fix warning when publishing. (#546)

Author: kenzieschmoll

packages/devtools/pubspec.yaml

@@ -19,6 +19,7 @@ dependencies:
   intl: ^0.15.0
   js: ^0.6.1+1
   meta: ^1.1.0
+  path: ^1.6.0
   pedantic: ^1.4.0
   platform_detect: ^1.3.5
   rxdart: ^0.21.0