Drop service_plan_guid from query param

  It should never have worked
CCNG accepts "extra" information

[#46132685]
Document logging configuration
WIP for buildpack cache
Add specs for upload buildpack cache
Refactor LegacyStaging to Staging
Provide buildpack cache download URI in staging request
Provide public aws download URL for app package
Fix link in README

- Max and David
Make db:migrate rake task log to stdout [#44486581]
Add description of log levels to README

- Bleicke and Max
Remove services lifecycle from config [#48282639]
support quota definitions with unlimited services

[#48287047]
Return a meaningful message when space guid is invalid in create service requests.
Adding support for oracle varchars that cannot tell the difference
between null and ""
Updated model tests to allow nil for host but dis allow nil from making
it into the database unless we're using oracle.
Make host nillable but don't allow it to be committed to the database as
nil unless we're using Oracle
Mark apps as having failed to stage [#48212825]
Fix description in instances API spec
Refactor/Add HM_Respondent tests