Fixed typo (#3)

* Fixed typo

* Update plugin path

Author: Nyholm

.gitattributes

@@ -7,6 +7,5 @@ src/ export-ignore
 .prettyci.composer.json export-ignore
 .travis.yml export-ignore
 bref-extra export-ignore
-bchecksums.json export-ignore
+checksums.json export-ignore
 Makefile export-ignore
-

Readme.md

@@ -17,7 +17,7 @@ provider:
 
 plugins:
     - ./vendor/bref/bref
-    - ./vendor/bref/extra-layers # <----- Add the extra Serverless plugin
+    - ./vendor/bref/extra-php-extensions # <----- Add the extra Serverless plugin
 
 functions:
     console: