WIP: Implemented support for normal keyboards

[MattiaEffendi]

I've added the support for "standard" keyboards natively. List of things i still have to do:

• [x] Code
• [ ] Documentation

A test code could be the following:

@bot.command("keyboard")
def kb(chat, message):
	kb = botogram.Keyboard(one_time=True)
	kb[0].text("Simple text")
	kb[1].request_contact("Request contact")
	kb[2].request_location("Request location")
	chat.send("Message with a standard keyboard", attach=kb)
	
@bot.command("rem")
def rem(chat, message):
	chat.send("Keyboard removed", force_reply=True, remove_keyboard=True)

[MarcoBuster]

Hi @MattiaEffendi and thank you for your PR! You should check the Travis-CI log, because it seems that there are errors. Please write the documentation and the changelog according to the overall style. If you have questions write in our botogram devs group :)

[MarcoBuster]

Hi @MattiaEffendi! Updates? :D