implement Espresso tests with benchmarking flows

[mrsasha]

This would be the test flow to be implemented for benchmarking (using mock web server for responses)

1. open app (Search Fragment)
2. press search button (starts 4 calls)
3. wait for search results to open
4. scroll to the bottom of search results
5. scroll to the top of search results

--- repeat for results 0-9

1. open details of result (0)
2. wait for details to load
3. go back

--- end repeat

1. go back to search fragment

When this is automated, we would then watch for max CPU and memory usage, for an average of 5-10 runs.