go run for ocagent from sources and clone repo blurb (#446)

* `go run` for ocagent from sources and clone repo blurb

Fix #445

* Small fixes

* PR Comments

Author: Paulo Janotti

README.md

@@ -210,7 +210,8 @@ zpages:
 
 ### <a name="agent-usage"></a>Usage
 
-The ocagent can be run directly from sources, binary, or a Docker image.
+The ocagent can be run directly from sources, binary, or a Docker image. If you are planning to run from sources or build
+on your machine start by cloning the repo using `go get -d github.com/census-instrumentation/opencensus-service`.
 
 It is recommended that you use the latest [release](https://github.com/census-instrumentation/opencensus-service/releases).
 
@@ -219,7 +220,7 @@ The minimum Go version required for this project is Go 1.11.4.
 1. Run from sources:
 
 ```shell
-$ GO111MODULE=on go get github.com/census-instrumentation/opencensus-service/cmd/ocagent
+$ GO111MODULE=on go run github.com/census-instrumentation/opencensus-service/cmd/ocagent --help
 ```
 
 2. Run from binary (from the root of your repo):
@@ -322,13 +323,14 @@ sampling:
 
 > It is recommended that you use the latest [release](https://github.com/census-instrumentation/opencensus-service/releases).
 
-The collector can be run directly from sources, binary, or a Docker image.
+The collector can be run directly from sources, binary, or a Docker image. If you are planning to run from sources or build
+on your machine start by cloning the repo using `go get -d github.com/census-instrumentation/opencensus-service`.
 
 The minimum Go version required for this project is Go 1.11.4.
 
 1. Run from sources:
 ```shell
-$ GO111MODULE=on go run github.com/census-instrumentation/opencensus-service/cmd/occollector
+$ GO111MODULE=on go run github.com/census-instrumentation/opencensus-service/cmd/occollector --help
 ```
 2. Run from binary (from the root of your repo):
 ```shell
@@ -409,4 +411,4 @@ queued-exporters:
 [gitter-image]: https://badges.gitter.im/census-instrumentation/lobby.svg
 [gitter-url]: https://gitter.im/census-instrumentation/lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
 [codecov-image]: https://codecov.io/gh/census-instrumentation/opencensus-service/branch/master/graph/badge.svg
-[codecov-url]: https://codecov.io/gh/census-instrumentation/opencensus-service/branch/master/
+[codecov-url]: https://codecov.io/gh/census-instrumentation/opencensus-service/branch/master/