Reduce the training cost of bazookas

[smaug81243]

I would love to implement bazookas into my typical army composition but with how frequently they end up dying it seems insane to do so when each bazooka costs over 200 oil each. It is hard enough to accumulate oil as is. Reduce the training cost so that it makes sense to use them more.

 

[SiuYin]

Given the fact that Bazooka is easily get killed in battle, the training time should also be reduced
I think 3m20s is an appropriate value (same as shooter for same troop size)