Linter config lints test directory (#99)

Modify eslint config to lint ./test/

packages/ripple-binary-codec/tsconfig.eslint.json

@@ -3,5 +3,5 @@
 {
     // extend your base config so you don't have to redefine your compilerOptions
     "extends": "./tsconfig.json",
-    "include": ["src/**/*.ts"]
+    "include": ["src/**/*.ts", "test/**/*.js"]
   }