Allow manual configuration of gas price when using aragonCLI in Terminal

[chrishobcroft]

🚀 Feature

When using aragonCLI within Terminal, I would like to be able to manually configure the gas price.

Currently, it appears that this is hard coded to a gas price of 10 gwei, which for example made the installation of an app to a DAO (0.00783171 Ether = $1.87 at time of writing) more expensive than installing many paid-for apps from Apple App Store onto an iPhone. Furthermore, using dao acl to create new permissions using CLI is similarly expensive, which means that configuring apps with many permissions on acl is not feasible.

I understand from @0x6431346e that you can specify gasPrice in the truffle network, however as a non-user of truffle (like many end users), I cannot use this, so I appear to be stuck with the expensive hardcoded 10 gwei gas price, which makes all my aragonCLI calls very expensive.

Related: #353
Related: #346

Have you read the Contributing Guidelines on issues?

Yes.

Motivation

To reduce the cost of configuring a mainnet DAO using aragonCLI - right now it's waay too expensive.

Furthermore, as referenced by @luisivan in this issue, running dao new on mainnet comes at high costs.

Pitch

Currently, to install an app into a DAO using aragonCLI, it costs $1.87 in gas, using a hard-coded gas price of 10 gwei.

Recommended gas price right now as per ethgasstation.info is 1 gwei, which means that the total cost could have been $0.187 - a reduction of 90% in operating costs.

This limits my freedom due to high costs of operating on the Aragon network.

By implementing such a feature, it will reduce the costs and lower the barriers to entry for users.

[sohkai]

It would be nice if the command prompted the user to suggest a gas price or defaulted to an api (e.g. ethgasstation). 10 should be used as the worst-case fallback if we're at a lack for a better number.

[lkngtn]

Agree strongly with this!

I would also love to have an estimate of total cost which is confirmed by the user by default.