Add a with-fixtures helper for running tests in fixtures
Add a with-fixtures helper for running tests in fixtures

Unfortunately, fixture execution is normally tied to `deftest`. Because
`deftest` can't be given a dynamic variable name, it can't really be
used in a loop to test multiple pieces of code that do the same thing.
`with-fixtures` is a new macro which separates invoking fixtures from
`deftest`. Any code inside a call to `with-fixtures` will be surrounded
by the fixtures for the current namespace.

mullr/puppetdb,grimradical/puppetdb,kbrezina/puppetdb,shrug/puppetdb,melissa/puppetdb,kbrezina/puppetdb,mullr/puppetdb,wkalt/puppetdb,highb/puppetdb,wkalt/puppetdb,github/puppetlabs-puppetdb,nfagerlund/puppetdb,waynr/puppetdb,rbrw/puppetdb,kbarber/puppetdb,ajroetker/puppetdb,rbrw/puppetdb,jantman/puppetdb,kbarber/puppetdb,senior/puppetdb,rbrw/puppetdb,puppetlabs/puppetdb,melissa/puppetdb,johnduarte/puppetdb,shrug/puppetdb,github/puppetlabs-puppetdb,mullr/puppetdb,johnduarte/puppetdb,cprice404/puppetdb,rbrw/puppetdb,senior/puppetdb,shrug/puppetdb,puppetlabs/puppetdb,wkalt/puppetdb,cprice404/puppetdb,waynr/puppetdb,ajroetker/puppetdb,ajroetker/puppetdb,nfagerlund/puppetdb,kbarber/puppetdb,cprice404/puppetdb,grimradical/puppetdb,jantman/puppetdb,waynr/puppetdb,johnduarte/puppetdb,puppetlabs/puppetdb,melissa/puppetdb,kbrezina/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,wkalt/puppetdb,grimradical/puppetdb,highb/puppetdb,kbarber/puppetdb,senior/puppetdb,highb/puppetdb,waynr/puppetdb,rbrw/puppetdb,mullr/puppetdb,kbrezina/puppetdb,jantman/puppetdb,johnduarte/puppetdb,mullr/puppetdb,shrug/puppetdb,grimradical/puppetdb,highb/puppetdb,ajroetker/puppetdb,github/puppetlabs-puppetdb,senior/puppetdb,nfagerlund/puppetdb