Bump acorn from 5.7.3 to 5.7.4 in /example

Bumps [acorn](https://github.com/acornjs/acorn) from 5.7.3 to 5.7.4.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](acornjs/acorn@5.7.3...5.7.4)

Signed-off-by: dependabot[bot] <support@github.com>

example/yarn.lock

@@ -1090,9 +1090,9 @@ acorn-walk@^6.0.1:
   integrity sha512-7evsyfH1cLOCdAzZAd43Cic04yKydNx0cF+7tiA19p1XnLLPU4dpCQOqpjqwokFe//vS0QqfqqjCS2JkiIs0cA==
 
 acorn@^5.5.3:
-  version "5.7.3"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.3.tgz#67aa231bf8812974b85235a96771eb6bd07ea279"
-  integrity sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==
+  version "5.7.4"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.4.tgz#3e8d8a9947d0599a1796d10225d7432f4a4acf5e"
+  integrity sha512-1D++VG7BhrtvQpNbBzovKNc1FLGGEE/oGe7b9xJm/RFHMBeUaUGpluV9RLjZa47YFdPcDAenEYuq9pQPcMdLJg==
 
 acorn@^6.0.1:
   version "6.3.0"
@@ -5088,9 +5088,7 @@ react-is@^16.8.1, react-is@^16.8.4, react-is@^16.9.0:
   integrity sha512-BXUMf9sIOPXXZWqr7+c5SeOKJykyVr2u0UDzEf4LNGc6taGkQe1A9DFD07umCIXz45RLr9oAAwZbAJ0Pkknfaw==
 
 "react-native-openalpr@file:..":
-  version "1.2.0"
-  dependencies:
-    react-native-permissions "^2.0.0"
+  version "2.1.1"
 
 react-native-permissions@^2.0.0:
   version "2.0.0"