Bump github.com/newrelic/go-agent (#234)

Bumps [github.com/newrelic/go-agent](https://github.com/newrelic/go-agent) from 2.14.1+incompatible to 2.15.0+incompatible.
- [Release notes](https://github.com/newrelic/go-agent/releases)
- [Changelog](https://github.com/newrelic/go-agent/blob/master/CHANGELOG.md)
- [Commits](https://github.com/newrelic/go-agent/compare/v2.14.1...v2.15.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/honeybadger-io/honeybadger-go v0.5.0
 	github.com/kardianos/osext v0.0.0-20170510131534-ae77be60afb1 // indirect
 	github.com/matoous/go-nanoid v0.0.0-20181114085210-eab626deece6
-	github.com/newrelic/go-agent v2.14.1+incompatible
+	github.com/newrelic/go-agent v2.15.0+incompatible
 	github.com/prometheus/client_golang v0.9.4
 	github.com/sirupsen/logrus v1.4.2
 	github.com/stretchr/testify v1.4.0

go.sum

@@ -164,6 +164,8 @@ github.com/moul/http2curl v1.0.0/go.mod h1:8UbvGypXm98wA/IqH45anm5Y2Z6ep6O31QGOA
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/newrelic/go-agent v2.14.1+incompatible h1:rh+3g1mhz8WH3VD/ORq3QhQz4iqaClBlQ6q9KInojyE=
 github.com/newrelic/go-agent v2.14.1+incompatible/go.mod h1:a8Fv1b/fYhFSReoTU6HDkTYIMZeSVNffmoS726Y0LzQ=
+github.com/newrelic/go-agent v2.15.0+incompatible h1:IB0Fy+dClpBq9aEoIrLyQXzU34JyI1xVTanPLB/+jvU=
+github.com/newrelic/go-agent v2.15.0+incompatible/go.mod h1:a8Fv1b/fYhFSReoTU6HDkTYIMZeSVNffmoS726Y0LzQ=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.10.1/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.7.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=