chore(core): add sudo to main commands

chore(core): add Gulp global binary
chore(core): try to fix Travis connection problem
chore(core): try to fix connection again
chore(core): test destruction for debugging
chore(core): add sudo to debug problem
chore(core): keep on trying to fix connection
chore(core): keep trying to fix Travis
Revert "chore(core): keep trying to fix Travis"

This reverts commit 0ffc928ff074f6cf5c7d9eba1963d7a463435325.
Revert "chore(core): keep on trying to fix connection"

This reverts commit 6b71a4c2721079278afa613faa114334f497c8d1.
Revert "chore(core): add sudo to debug problem"

This reverts commit 9b5c19eac831b4cb90bd86cfdf1a6f6b8c2e9eb5.
Revert "chore(core): test destruction for debugging"

This reverts commit 7fe4066a3d1c2a187405c4c3656f2354c95d79af.
chore(core): add sudo again to fix the problem
chore(core): try to locate nodejs on Travis
chore(core): symlink nodejs for Travis
chore(core): try aliasing nodejs to node
chore(core): add sudo to symlinking nodejs
chore(core): fix Travis problem hopefully
chore(core): add gulp global binary to Travis
chore(core): use Gulp global binary for testing
chore(core): try looking up Gulp in local folders