fix issues with brew

fix brew.sh

# http://stackoverflow.com/questions/14113427/brew-update-failed
cd $(brew --prefix)
git reset --hard HEAD

# cellar on hpcc cluster
# --prefix=~/.linuxbrew/Cellar

git clean -df

brew update

# on fedora, we have a cyclic dependency
# descirbed here: https://github.com/Homebrew/linuxbrew/issues/609

# is this works cool, else follow installing some of the dependencies first (below)
brew install gcc --cc=gcc

# gcc deps (one may encounter more issues)
brew install xz --cc=gcc