chore(package): update pg to version 4.5.6 (#6021)
chore(package): update pg to version 4.5.6 (#6021)

https://greenkeeper.io/
abegines/sequelize,Americas/sequelize,PhinCo/sequelize,sequelize/sequelize,sequelize/sequelize,grimurd/sequelize,sequelize/sequelize,toddbluhm/sequelize,Verdier/sequelize,Americas/sequelize,inDream/sequelize,cbauerme/sequelize,Alexsey/sequelize,jayprakash1/sequelize,felixfbecker/sequelize,paolord/sequelize,gintsgints/sequelize,topikachu/sequelize,konnecteam/sequelize,overlookmotel/sequelize,konnecteam/sequelize,darwinserrano/sequelize,nemisj/sequelize,gutobortolozzo/sequelize,seshness/sequelize,inDream/sequelize,majorleaguesoccer/sequelize,alekbarszczewski/sequelize,sorin/sequelize,tornillo/sequelize,PsiXdev/sequelize,gorangajic/sequelize,jayprakash1/sequelize,yonjah/sequelize,Wsiegenthaler/sequelize,overlookmotel/sequelize,StefanoDalpiaz/sequelize,pola88/sequelize,yjwong/sequelize,p0vidl0/sequelize,mikeringrose/sequelize