Improve test times by patching the number of iterations on the key

[nir0s]

Currently, they're set to 1000000. Changing to about a 100 will reduce test times to just several seconds.

[nir0s]

https://github.com/nir0s/ghost/pull/139/files#diff-b67911656ef5d18c4ae36cb6741b7965R38 in #139 patches in when running make test. Now we should use make test in Travis instead of tox.