.travis.yml: ++memory info in after_failure
.travis.yml: ++memory info in after_failure

Add a bunch of memory-related commands so we can try to see where all of
the memory is going and why we are getting OOMs.

Refs: #1045

guilhermebr/tsuru,ArxdSilva/tsuru,cezarsa/tsuru,firebitsbr/tsuru,firebitsbr/tsuru,gciotta/tsuru,gwmoura/tsuru,tuxmonteiro/tsuru,gwmoura/tsuru,ggarnier/tsuru,cgvarela/tsuru,hcxiong/tsuru,guilhermebr/tsuru,ArxdSilva/tsuru,hcxiong/tsuru,kgrvamsi/tsuru,cgvarela/tsuru,tsuru/tsuru,4eek/tsuru,tsuru/tsuru,jblancett/tsuru,Endika/tsuru,RichardKnop/tsuru,ArxdSilva/tsuru,kgrvamsi/tsuru,ggarnier/tsuru,4eek/tsuru,cgvarela/tsuru,ggarnier/tsuru,Endika/tsuru,gciotta/tsuru,RichardKnop/tsuru,gciotta/tsuru,mderaldo/tsuru,guilhermebr/tsuru,jblancett/tsuru,mderaldo/tsuru,ArxdSilva/tsuru,tsuru/tsuru,RichardKnop/tsuru,mderaldo/tsuru,hugoantunes/tsuru,cezarsa/tsuru,gwmoura/tsuru,guilhermebr/tsuru,4eek/tsuru,tuxmonteiro/tsuru,hugoantunes/tsuru,cezarsa/tsuru,ggarnier/tsuru,jblancett/tsuru,tuxmonteiro/tsuru,tsuru/tsuru,kgrvamsi/tsuru,firebitsbr/tsuru,hcxiong/tsuru,Endika/tsuru,cezarsa/tsuru