doc(tools/flyspeck_code): update README
feat(tools/smt2_stat): add print_infix_formula
chore(travis): update secure keys
doc(README.md): use shield.io icon for builds
chore(travis): install cmake and automake for OSX build
chore(CodeCoverage): exclude ones with 'include/*'
chore(travis): fix shallow repo before push to bitbucket