Update the ESLint dependencies, and also tweak the no-multiple-empty-lines rules

Since multiple empty lines is virtually unused in the code-base, and the few cases that do exist look like "typos", let's enforce greater consistency here; please see https://eslint.org/docs/rules/no-multiple-empty-lines.

test/unit/function_spec.js

@@ -440,7 +440,6 @@ describe('function', function() {
     });
   });
 
-
   describe('PostScriptCompiler', function() {
     function check(code, domain, range, samples) {
       var compiler = new PostScriptCompiler();