(prometheus) support POST for query and query_range

Reported in #11176

build: upgrades build pipeline from CircleCI 1.0 -> 2.0

My hope is that headers will make it easier to read
when people post issues.

* mayli-master:
  Use B/s instead Bps for Bytes per second

* 'master' of https://github.com/mayli/grafana:
  Use B/s instead Bps for Bytes per second

* 'master' of github.com:grafana/grafana: (24 commits)
  docs: update latest to 5.0.1
  push 5.0.1 to package cloud
  changelog: adds release date for 5.0.1
  bump master build to 5.1.0-pre1
  move quota to dedicated service
  rename Context to ReqContext
  changelog: note about closing #11145 and #11127
  docs: adds note about closing #10632
  removes commented code
  removes unused variables
  upgrade to go 1.10
  alerting: fixes validation error when saving alerts in dash
  add csv templating format
  docs: note about closing #11046
  docs: adds note about #10942
  Documentation: path "~/go" to "$GOPATH"
  Update ROADMAP.md
  move Context and session out of middleware
  only use jwt token if it contains an email address
  hide row actions for viewers
  ...

(cloudwatch) support high resolution query

* 'cw_high_resolution' of https://github.com/mtanda/grafana:
  fix, set default highResolution setting
  support cloudwatch high resolution query

move quota to dedicated service

fix query condition docs

move Context and session out of middleware

Upgrade golang to 1.10

Documentation fix: "~/go" to "$GOPATH"

alerting: fixes validation error when saving alerts in dash

only use jwt token if it contains an email address

add comma templating format

If a panelId in the dashboard json is set to zero then the validation
silently fails. Instead of returning an error, it just ignores alerts and
saves the dashboard.

Add metrics that triggered alert to description in OpsGenie.