In this commit, we put the context initialization inside
openChannelAndAssert, thus saving us a few lines and making sure the
context is always properly handled.
This commit uses the require library for the link nodes garbage collect
test and fixes a flake that was discovered while hunting for other
flakes. Some times the channel isn't updated fast enough so we can
detech it on first try. So we give it a few more tries to stabilize the
test.
This commit creates the file lnd_misc_test.go to hold all miscellaneous
tests in the file lnd_test.go. From now on, the lnd_test.go will only be
responsible for handling the "top" level functionalities such as
splitting test cases and run them. Newly created test cases should find
their places in the related test files, or create new one when needed.
