Clean up: Remove unused files

.travis/.gitignore-release

-# Realizing whitelist by excluding everything and specifying exceptions.
-
-/*
-
-!/built
-!/tools
-!/elasticsearch
-!/package.json
-!/.travis.yml
-!/appveyor.yml

.travis/release.sh

-#!/bin/bash
-
-echo "Starting releasing task"
-openssl aes-256-cbc -K $encrypted_ceda82069128_key -iv $encrypted_ceda82069128_iv -in ./.travis/travis_rsa.enc -out travis_rsa -d
-cp travis_rsa ~/.ssh/id_rsa
-chmod 600 ~/.ssh/id_rsa
-echo -e "Host github.com\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
-git checkout -b release
-cp -f ./.travis/.gitignore-release .gitignore
-node ./.travis/shapeup.js
-git add --all
-git rm --cached `git ls-files --full-name -i --exclude-standard`
-git config --global user.email "AyaMorisawa4869@gmail.com"
-git config --global user.name "Aya Morisawa"
-git commit -m "Release build for $TRAVIS_COMMIT"
-git push -f git@github.com:syuilo/misskey release
-echo "Finished releasing task"

.travis/shapeup.js

-'use strict'
-
-const fs = require('fs')
-const filename = process.argv[2] || 'package.json'
-
-fs.readFile(filename, (err, data) => {
-    if (err) process.exit(2)
-    const object = JSON.parse(data)
-    delete object.devDependencies
-    fs.writeFile(filename, JSON.stringify(object, null, '\t') + '\n', err => {
-        if (err) process.exit(3)
-    })
-})