Test tries to get the block

Instead of running a script we now use the mocha testing framework which
provides much better output and makes it much easier to add testcases.

Update CI to use new docker image, since we now need to run node and npm
as part of our tests.

The IPV6 addresses returned from the geth node were not working on CI so
we convert them to IPV4 addresses.

Add installed go binaries location to user's path

This should mitigate the readme going out of date whenever we update go.

If the flag is set then the 'gasLimit' and 'baseFeePerGas' fields will
not be returned on RPC blocks.

…patibility

One for tests with state one for tests without.

This makes executing each batch of tests easier because we can just grep
for the describe headings.

Just to further signify that it is not for standalone use.

If the state is missing for gasLimit or baseFeePerGas or if there is
some other failure when retrieving them then do not add them as fields
to the block. Preivously in some cases a default value would have been
added to the block and returned.