MM-27918 In-Product notices support (#15316)

go.mod

@@ -3,6 +3,7 @@ module github.com/mattermost/mattermost-server/v5
 go 1.14
 
 require (
+	github.com/Masterminds/semver/v3 v3.1.0
 	github.com/Masterminds/squirrel v1.4.0
 	github.com/NYTimes/gziphandler v1.1.1
 	github.com/RoaringBitmap/roaring v0.5.0 // indirect
@@ -80,6 +81,7 @@ require (
 	github.com/pelletier/go-toml v1.8.0 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.7.1
+	github.com/reflog/dateconstraints v0.2.1
 	github.com/prometheus/client_model v0.2.0 // indirect
 	github.com/prometheus/common v0.12.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20190728182440-6a916e37a237 // indirect