add max_post_size to testing config
add max_post_size to testing config

willmclaren/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest,ens-lgil/ensembl-rest,helensch/ensembl-rest,helensch/ensembl-rest,willmclaren/ensembl-rest,willmclaren/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest,helensch/ensembl-rest