Run go mod tidy over Go projects

Author: Sourcegraph Bot

go.sum

@@ -1,7 +1,5 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/opentracing-contrib/go-stdlib v0.0.0-20190510164024-2b2d2700a3b7 h1:sRfr13qLClTOCZ8f2tFb0k9m1TZayEUz1fpWL38ocnE=
-github.com/opentracing-contrib/go-stdlib v0.0.0-20190510164024-2b2d2700a3b7/go.mod h1:PLldrQSroqzH70Xl+1DQcGnefIbqsKR7UDaiux3zV+w=
 github.com/opentracing-contrib/go-stdlib v0.0.0-20190519235532-cf7a6c988dc9 h1:QsgXACQhd9QJhEmRumbsMQQvBtmdS0mafoVEBplWXEg=
 github.com/opentracing-contrib/go-stdlib v0.0.0-20190519235532-cf7a6c988dc9/go.mod h1:PLldrQSroqzH70Xl+1DQcGnefIbqsKR7UDaiux3zV+w=
 github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsqf19k25Ur8rU=
@@ -13,6 +11,7 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=