use `net/mocknet` in integration tests

refactor(epictest) Core

refactor: extract repo

fix

move core

cc @jbenet

It's now possible to produce the DHT issues without process
orchestration.

Test1KBInstantaneous fails

@jbenet @whyrusleeping

pprof cannot be used reliably on OS X. This provides two make tasks to
collect and analyze profiling data.

To run profiling in a dockerized linux environment...
```
make // or `make collect`
```

To analyze results on host machine...
```
make analyze
```

@jbenet @whyrusleeping

@whyrusleeping @jbenet this is a WIP with the DHT.

wip

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

Conflicts:
	epictest/addcat_test.go
	exchange/bitswap/testnet/peernet.go
	exchange/bitswap/testutils.go
	routing/mock/centralized_server.go
	routing/mock/centralized_test.go
	routing/mock/interface.go

fix(routing/mock) fill in function definition

https://travis-ci.org/jbenet/go-ipfs/jobs/45000756

cc @whyrusleeping @jbenet

lol this is starting to happen pretty often

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

so it'll be easier to create another implementation using the new
mocknet

dht fixes

TestProversMany still fails