Merge pull request ethereum#14556 from ethereum/homebrew-update

Upgrade homebrew packages

Author: r0qs

.circleci/osx_install_dependencies.sh

@@ -52,6 +52,8 @@ function validate_checksum {
 
 if [ ! -f /usr/local/lib/libz3.a ] # if this file does not exists (cache was not restored), rebuild dependencies
 then
+  brew update
+  brew upgrade
   brew install boost
   brew install cmake
   brew install wget