Fix support for ask-cli 2.30.0 and above

[ilovelinux]

Proposed Changes

Since ask-cli 2.30.0 introduces a breaking change (see alexa/ask-cli#485), I edited accordingly the headers parsing function.

I also dropped support for ask-cli 2.29.2 and older.

Fixes #1568, jovotech/jovo-cli#357
Closes #1575 (not working)

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• The code has been tested

[aswetlow]

Thank you @ilovelinux

[jankoenig]

Thank you!