Work on install and monitoring builds:

  - [x] `make install` should cleanup `$GOPATH/pkg/<test-flight>`
  - [x] monitor output stream from `attach` channel and `listen` for errors
    - [x] allow user cancel which grounds build => but user must manually
          delete intermediate container.
Work on warning while launching container:

  - [x] Allow launch of existing container but with a warning (`launchcommand todo`)
Merge pull request #10 from JasonGiedymin/dev/0.9.7/user-cancel

Dev/0.9.7/user cancel