Remove more rules covered by the ESLint preset

[ruiquelhas]

Remove the following rules, which are already available on ESLint, and should be part of our preset:

• requirePaddingNewLineAfterVariableDeclaration (covered by newline-after-var)
• requirePaddingNewLinesBeforeLineComments (covered by lines-around-comment)

[rplopes]

Update: the first rule of that list (requirePaddingNewLineAfterVariableDeclaration) has already been removed as part of #13. So now there's only the last rule (requirePaddingNewLinesBeforeLineComments) to remove (done in #14)