Add go-bindata as a module dependency

This adds https://github.com/jteeuwen/go-bindata as a module dependency
as the make target 'build' will result in it's addition.

go.mod

@@ -32,6 +32,7 @@ require (
 	github.com/guregu/null v3.4.0+incompatible
 	github.com/ikeikeikeike/go-sitemap-generator v1.0.1
 	github.com/imdario/mergo v0.3.7 // indirect
+	github.com/jteeuwen/go-bindata v3.0.7+incompatible // indirect
 	github.com/jtolds/gls v4.2.1+incompatible // indirect
 	github.com/kylemcc/twitter-text-go v0.0.0-20180726194232-7f582f6736ec
 	github.com/lunixbochs/vtclean v1.0.0 // indirect

go.sum

@@ -83,6 +83,8 @@ github.com/ikeikeikeike/go-sitemap-generator v1.0.1 h1:49Fn8gro/B12vCY8pf5/+/Jpr
 github.com/ikeikeikeike/go-sitemap-generator v1.0.1/go.mod h1:QI+zWsz6yQyxkG9LWNcnu0f7aiAE5tPdsZOsICgmd1c=
 github.com/imdario/mergo v0.3.7 h1:Y+UAYTZ7gDEuOfhxKWy+dvb5dRQ6rJjFSdX2HZY1/gI=
 github.com/imdario/mergo v0.3.7/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
+github.com/jteeuwen/go-bindata v3.0.7+incompatible h1:91Uy4d9SYVr1kyTJ15wJsog+esAZZl7JmEfTkwmhJts=
+github.com/jteeuwen/go-bindata v3.0.7+incompatible/go.mod h1:JVvhzYOiGBnFSYRyV00iY8q7/0PThjIYav1p9h5dmKs=
 github.com/jtolds/gls v4.2.1+incompatible h1:fSuqC+Gmlu6l/ZYAoZzx2pyucC8Xza35fpRVWLVmUEE=
 github.com/jtolds/gls v4.2.1+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/juju/ansiterm v0.0.0-20180109212912-720a0952cc2a h1:FaWFmfWdAUKbSCtOU2QjDaorUexogfaMgbipgYATUMU=