input: Write a function to insert a blog post into a SQLite database using the given title and content.
  assert insert_blog_post('Test Title', 'Test Content') == 'Blog post saved successfully!'
  assert insert_blog_post('Another Title', 'Another Content') == 'Blog post saved successfully!'
  assert insert_blog_post('Hello World', 'This is a blog post content.') == 'Blog post saved successfully!'
output: import sqlite3
  
  def insert_blog_post(title, content):
      conn = sqlite3.connect('blog_posts.db')
      cursor = conn.cursor()
      cursor.execute('''
      CREATE TABLE IF NOT EXISTS posts (
          id INTEGER PRIMARY KEY AUTOINCREMENT,
          title TEXT NOT NULL,
          content TEXT NOT NULL
      )
      ''')
      cursor.execute('INSERT INTO posts (title, content) VALUES (?, ?)', (title, content))
      conn.commit()
      conn.close()
      return 'Blog post saved successfully!'