Update .npmignore

Remove src from gitignore

Author: Javier Morant

.npmignore

@@ -1,7 +1,6 @@
 examples
 flow-typed
 node_modules
-src
 .circleci
 .github
 coverage
@@ -10,4 +9,4 @@ coverage
 .flowconfig
 .eslintignore
 CODE_OF_CONDUCT.md
-README.md
+README.md