* Update `add_license` script
* run script
* add `remove duplicate lines script` and run it
* Revert changes `English spaces`
* strip whitespaces
* Revert `GPL` in files with `apache/mit license`
* don't append `gpl license` in files with other lic
* Don't append `gpl header` in files with other lic.
* re-ran script
* include c and cpp files too
* remove duplicate header
* rebase nit
* Async RPC
* Limiting number of transactions in queue
* Fixing tests
* Bumping serde and jsonrpc-core
* serde updated to 0.8
* fixed failing tests
* Bumping ipc server
* Fixing API for endpoints
* Experimenting with tests without --release mode