Launch older scala-cli version without --cli-scala-version

[lwronski]

Is your feature request related to a problem? Please describe.
To enforce to use artefacts from 2.12, user have to specify another one parameter --cli-scala-version . If someone use Scala CLI 0.1.3 the following command throw error:

lwronski@VL-D-0317 scala-cli % scala-cli --cli-version 0.1.1  about                         
Fetching Scala CLI 0.1.1
Error downloading org.virtuslab.scala-cli:cli_2.13:0.1.1
  not found: /Users/lwronski/.ivy2/local/org.virtuslab.scala-cli/cli_2.13/0.1.1/ivys/ivy.xml
  not found: https://repo1.maven.org/maven2/org/virtuslab/scala-cli/cli_2.13/0.1.1/cli_2.13-0.1.1.pom
  not found: https://oss.sonatype.org/content/repositories/snapshots/org/virtuslab/scala-cli/cli_2.13/0.1.1/cli_2.13-0.1.1.pom

Describe the solution you'd like
Scala CLI should accept to download older version of scala-cli, so the following command should work:

scala-cli % scala-cli --cli-version 0.1.1  about