(Linux) Add Proxy configuration support

### Expected Behaviour

When using the aio-cli behind a corporate proxy the proxy should be somehow configurable or it should be able to use the environment variables

### Actual Behaviour

aio-cli cannot connect to the internet for example to load the project list from AEMaaCS account.

### Reproduce Scenario (including but not limited to)

Be behind a corporate proxy like proxy.example:8080 which supports NTLM authentication.

#### Steps to Reproduce
Launch aio and try to access your AEMaaCS information during the init steps.

#### Platform and Version
Linux Ubuntu (18.04)
aio-cli:Latest
node/npm: LTS

#### Sample Code that illustrates the problem
Cant priovide this only had temporary access to a AEMaaCS test account during AdaptTo() 2020

#### Logs taken while reproducing problem
Connection failed error message