Always use debug_inspector API for bactrace info
Refactoring frame command
Move State classes to their own files
Refactoring: move some methods to a better place

They should probably go into their own formatting class but I want to do
this step by step.
Bump codeclimate-test-reporter dependency
Remove unimplemented command from README [ci skip]
Should definitely fix #93

Our calced_stack_size should be reliable enough at this stage (I'm
getting some failures in 2.0 I think due to missing backports but it's
ok for now). It also has the advantage that we can easily "fake it" to
properly ignore byebug internal frames.
Whitespace
Skip failing test

I fixed this test a while ago but it's happening again (in a different
form). Full threading support is coming soon so I'm going to skip this
for now.
Remove unnecessary reader & writer
Migrate restart tests to use debug_code method
Remove unnecessary line

Don't really need that flexibility.
Refactor how debugged program is set from cmd line

This way we do not touch ARGV or $PROGRAM_NAME and the restart command
becomes simpler.
Cleaner test interface inspection
Migrate all the test suite to use debug_code
Fill up skipped test
Install all deps for both development and test
Fix pry command and tests
Minor style and whitespace changes
Upgrade codeclimate-test-reporter