Unpin GCP test requirement
Unpin GCP test requirement

Keeping the `google-cloud-bigquery` dependency pinned to a version prevents this packages from being installable alongside `google-cloud-bigquery` in a more recent version. Since the comment above the dependency states that it is only needed for tests, I would guess that this SDK can work with newer versions.
markflyhigh/incubator-beam,RyanSkraba/beam,charlesccychen/beam,charlesccychen/beam,mxm/incubator-beam,robertwb/incubator-beam,apache/beam,chamikaramj/beam,markflyhigh/incubator-beam,rangadi/beam,robertwb/incubator-beam,chamikaramj/beam,charlesccychen/beam,apache/beam,RyanSkraba/beam,markflyhigh/incubator-beam,robertwb/incubator-beam,markflyhigh/incubator-beam,rangadi/beam,chamikaramj/beam,charlesccychen/beam,apache/beam,lukecwik/incubator-beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,charlesccychen/incubator-beam,chamikaramj/beam,lukecwik/incubator-beam,lukecwik/incubator-beam,chamikaramj/beam,apache/beam,rangadi/beam,robertwb/incubator-beam,charlesccychen/beam,apache/beam,rangadi/incubator-beam,rangadi/beam,charlesccychen/incubator-beam,chamikaramj/beam,apache/beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,chamikaramj/beam,apache/beam,chamikaramj/beam,charlesccychen/incubator-beam,iemejia/incubator-beam,rangadi/incubator-beam,rangadi/beam,apache/beam,mxm/incubator-beam,apache/beam,rangadi/beam,RyanSkraba/beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,iemejia/incubator-beam,rangadi/beam,apache/beam,lukecwik/incubator-beam,robertwb/incubator-beam,lukecwik/incubator-beam,chamikaramj/beam,robertwb/incubator-beam,charlesccychen/beam,lukecwik/incubator-beam,charlesccychen/beam,RyanSkraba/beam,RyanSkraba/beam,apache/beam,robertwb/incubator-beam,RyanSkraba/beam,lukecwik/incubator-beam,robertwb/incubator-beam,robertwb/incubator-beam,RyanSkraba/beam,chamikaramj/beam,rangadi/incubator-beam,robertwb/incubator-beam