Update StringScanner

Merge pull request #95 from Ponyboy47/master

Upgrade to swift 5.0

Swift 4.2 on Linux

Merge pull request #83 from nsomar/fix-codecov

Fix code coverage report

Merge pull request #72 from oarrabi/oarrabi/adding-tracker

adding tracker

Merge pull request #67 from oarrabi/oarrabi/adding-badges

Adding new badges

Merge pull request #63 from oarrabi/oarrabi/fixing-issue-when-root-ha…

…s-no-sub-commands

Fixing an issue when root does not have subcommands

Merge pull request #58 from oarrabi/oarrabi/fixing-lev-issue

Fixing levestein issue