go.mod: bump scylladb/gocql version

Now, scylla's fork of gocql in v1.5.0 is used for examples and testing.
The most important improvements include support for the CDC partitioner,
and a fix for tuple unmarshaling - the last field in the tuple could be
misrepresented as empty value when it actually was NULL.

go.mod

@@ -2,7 +2,7 @@ module github.com/scylladb/scylla-cdc-go
 
 go 1.14
 
-replace github.com/gocql/gocql => github.com/scylladb/gocql v1.4.3
+replace github.com/gocql/gocql => github.com/scylladb/gocql v1.5.0
 
 require (
 	github.com/gocql/gocql v0.0.0-20201215165327-e49edf966d90

go.sum

@@ -17,8 +17,8 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/scylladb/gocql v1.4.3 h1:gCfpHdRTLK5AsE1y2Mh8+dDPVa4VImUXfUjsCMjUdqc=
-github.com/scylladb/gocql v1.4.3/go.mod h1:S154F0u6zQlF3JjuHAidQIExQf9H45yT8z68h0FQYdU=
+github.com/scylladb/gocql v1.5.0 h1:tWaA08A8IprjgtBNPTVn8RkdiwEFUc85VcLA0E8JjH0=
+github.com/scylladb/gocql v1.5.0/go.mod h1:S154F0u6zQlF3JjuHAidQIExQf9H45yT8z68h0FQYdU=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=