Change .fire.inc to use the kv store and last aggregation
Fix typo (the the -> the) in fire.inc test description.
.fire.inc - > .inc
Allow an amount to be given to MetricStore.inc
Merge branch 'feature/issue-166-change-fire-inc-to-use-last-aggregation-and-the-kv-store' of github.com:praekelt/vumi-jssandbox-toolkit into feature/issue-166-change-fire-inc-to-use-last-aggregation-and-the-kv-store
MetricStore.inc -> MetricStore.fire.inc
Merge branch 'feature/issue-166-change-fire-inc-to-use-last-aggregation-and-the-kv-store' into develop