4.0.0-rc.1

• (a9f821b) Toggle content esckey property
• (98760ee) Bug fix letmein effect
• (0864e38) Bug fix on container close
• (1d55962) Add sizes when is an iframe
• (2ecf724) Bug fix callbacks
• (8ed416e) Prevent errors on close method
• (1ee35d7) Bug fix when close multiple modals with esc key
• (6fcd2e7) Add more features into loader
• (bde0ed5) Remove loader when custombox fail
• (9af5360) Add the container property into content object
• (3b40647) Bug fix content width
• (9e81bab) Minor changes into readme
• (dfc3c1d) chore(package): update dependencies (#207)
• (4bf6663) Bug fix version task