docs/installing: update year in copyright banner
docs/installing: update year in copyright banner

tuxmonteiro/tsuru,firebitsbr/tsuru,tsuru/tsuru,RichardKnop/tsuru,4eek/tsuru,tsuru/tsuru,ArxdSilva/tsuru,firebitsbr/tsuru,mderaldo/tsuru,tuxmonteiro/tsuru,4eek/tsuru,ggarnier/tsuru,mderaldo/tsuru,gciotta/tsuru,cgvarela/tsuru,kgrvamsi/tsuru,hcxiong/tsuru,RichardKnop/tsuru,ggarnier/tsuru,Endika/tsuru,ggarnier/tsuru,gciotta/tsuru,jblancett/tsuru,mderaldo/tsuru,ggarnier/tsuru,kgrvamsi/tsuru,hcxiong/tsuru,jblancett/tsuru,tsuru/tsuru,gwmoura/tsuru,tuxmonteiro/tsuru,guilhermebr/tsuru,Endika/tsuru,cezarsa/tsuru,cezarsa/tsuru,cezarsa/tsuru,cgvarela/tsuru,jblancett/tsuru,RichardKnop/tsuru,ArxdSilva/tsuru,ArxdSilva/tsuru,firebitsbr/tsuru,hcxiong/tsuru,gwmoura/tsuru,Endika/tsuru,cgvarela/tsuru,guilhermebr/tsuru,gwmoura/tsuru,tsuru/tsuru,cezarsa/tsuru,guilhermebr/tsuru,ArxdSilva/tsuru,guilhermebr/tsuru,gciotta/tsuru,4eek/tsuru,kgrvamsi/tsuru