Docker image v0.1.1 bloated

The size of the eosio/eosio-web-ide image has jumped from 828.68 MB to 1012.95 MB from version v0.1.0 to v0.1.1
The main culprit appears to be this command
```bash
tar -xjf boost_1_72_0.tar.bz2 && cd boost_1_72_0 && ... && rm -rf boost_1_72_0.tar.bz2 boost_1_71_0
```
You are `rm`ing `boost_1_71_0` instead of `boost_1_72_0`.

Also the eos install step has doubled in size, but that may just be the difference between eos 1.8.2 and 2.0.0