Update dependency google-cloud-bigquery to v1.28.2

Author: renovate[bot]

requirements.txt

@@ -5,7 +5,7 @@ chardet==3.0.4
 future==0.18.2
 google-api-core==1.22.1
 google-auth==1.21.0
-google-cloud-bigquery==1.27.2
+google-cloud-bigquery==1.28.2
 google-cloud-core==1.4.1
 google-crc32c==1.0.0
 google-resumable-media==1.0.0