Basic RPC and CLI Queries (#77)

- Adds ethermint query command (`emintcli query ethermint <query>`)
    - Supports block number, storage, code, balance lookups
- Implements RPC API methods `eth_blockNumber`, `eth_getStorageAt`, `eth_getBalance`, and `eth_getCode`
- Adds tester utility for RPC calls
    - Adheres to go test format, but should not be run with regular suite
    - Requires daemon and RPC server to be running
    - Excluded from `make test`, available with `make test-rpc`
- Implemented AppModule interface and added EVM module to app
    - Required for routing
- Implements `InitGenesis` (`x/evm/genesis.go`) and stubs `ExportGenesis`
- Modifies GenesisAccount to match expected format

Makefile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-PACKAGES=$(shell go list ./... | grep -Ev 'vendor|importer')
+PACKAGES=$(shell go list ./... | grep -Ev 'vendor|importer|rpc/tester')
 COMMIT_HASH := $(shell git rev-parse --short HEAD)
 BUILD_FLAGS = -tags netgo -ldflags "-X github.com/cosmos/ethermint/version.GitCommit=${COMMIT_HASH}"
 DOCKER_TAG = unstable
@@ -146,6 +146,9 @@ test-import:
 	--blockchain blockchain --timeout=5m
 	# TODO: remove tmp directory after test run to avoid subsequent errors
 
+test-rpc:
+	@${GO_MOD} go test -v --vet=off ./rpc/tester
+
 godocs:
 	@echo "--> Wait a few seconds and visit http://localhost:6060/pkg/github.com/cosmos/ethermint"
 	godoc -http=:6060