Pulls in v0.3.0 of google/go-dap; this version has some fixes and API improvements which service/dap will be able to leverage to clean up some code.
* Panic guard for DAP request handling * Use GetSeq * Re-vendor new version of go-dap * Remove comment * Update error message * Reuse er.Message in Format
* Initial implementation for 'dlv dap' * Fix Travis and AppVeyor failures * Address review comments * Address review comments * Regenrate documentation * Replace dap server printfs with log.Error * Update 'dap log' * Fix typos * Revert logflags changes that got mixed in by accident