Interactive exec CWD problem with TF JSON

[kke]

pharos exec -r master --first --tf-json e2e/dititalocean/tf.json

Generates:

NoMethodError: undefined method `open_channel' for nil:NilClass
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/transport/interactive_ssh.rb:22:in `run'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/transport/ssh.rb:104:in `block in interactive_session'
  /Users/kimmo/.rbenv/versions/2.6.3/lib/ruby/2.6.0/monitor.rb:230:in `mon_synchronize'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/transport/ssh.rb:104:in `interactive_session'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/exec_command.rb:34:in `block in run_interactive'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/exec_command.rb:31:in `map'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/exec_command.rb:31:in `run_interactive'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/exec_command.rb:16:in `execute'
  /Users/kimmo/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/clamp-1.2.1/lib/clamp/command.rb:63:in `run'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/command.rb:25:in `run'
  /Users/kimmo/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/clamp-1.2.1/lib/clamp/subcommand/execution.rb:11:in `execute'
  /Users/kimmo/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/clamp-1.2.1/lib/clamp/command.rb:63:in `run'
  /Users/kimmo/Projects/pharos-cluster/lib/pharos/command.rb:25:in `run'
  /Users/kimmo/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/clamp-1.2.1/lib/clamp/command.rb:132:in `run'
  bin/pharos:12:in `<top (required)>'

The json has ssh_key "./ssh_key.pem", fixable by making that path relative to PWD. Perhaps TF json parser needs to Dir.chdir(File.dirname(tf_json_path)) or something similar.