Add balancing bot

Adding a balancing bot like hodlerhacks.com . Idea: you define the coins you want to use and the percentage of them you want to have in your account. You define you base coin that will be used for the profit and the percentage of the coin will have to rise before the bot will sell, or to decrease before the bot buys. For example, if you have 3 coins and you define 33,3% per coin in your account and the one of them is rising by 5%, the bot will tale profit and distribute this profit to the other remaining coins to but them. So the balance is again 33,3% per coin in the account. They are many handy features but this is the idea.