[DRE-maint] Bug#976279: ruby-azure-core: ftbfs with ruby-faraday 1.0

[Pirate Praveen]

Package: ruby-azure-core
Version: 0.1.15-1
Severity: serious

Autopkgtest failed with this error (rebuild should see the same error)

/usr/lib/ruby/2.7.0/rubygems/dependency.rb:313:in `to_specs': Could not 
find 'faraday' (~> 0.9) - did find: [faraday-1.1.0] 
(Gem::MissingSpecVersionError)

Full log 
https://ci.debian.net/data/autopkgtest/testing/amd64/r/ruby-azure-core/8564802/log.gz

Though this package is replaced by ruby-azure-storage-common and 
ruby-azure-storage-blob. So this should be removed.