Repository: wso2/testgrid
Issue: The 'usage' help output is outdated

**Description:**
The help output provided right now is quite outdated. We need to fix this for this milestone.

```
[2018-01-23 18:33:01,687]  INFO {org.wso2.testgrid.core.command.HelpCommand} - 
usage: create-product-testplan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL
usage: run-testplan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL -t TESTPLAN_PATH -ir INFRA_REPO_PATH -sr SCENARIO_REPO_PATH
usage: generate-infrastructure-plan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL -i INFRASTRUCTURE_CONFIG_YAML_PATH
usage: generate-report -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL
usage: help
example: sh testgrid.sh create-product-testplan -p wso2is -v 5.3.0 -c LTS
example: sh testgrid.sh run-testplan -p wso2is -v 5.3.0 -c LTS -t ./my-testplan.yaml
```

https://github.com/wso2/testgrid/blob/master/core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java#L40

**Affected Product Version:**
0.9.0-m9

**OS, DB, other environment details and versions:**    
N/A

**Steps to reproduce:**
Run

`java -Dlog4j.configurationFile=/home/kasun/log4j2.xml -jar org.wso2.testgrid.core-0.9.0-SNAPSHOT-jar-with-dependencies.jar`

**Related Issues:**
N/A

Changed files:
core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java

diff --git a/core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java b/core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java
index d9145575..cc26f473 100644
--- a/core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java
+++ b/core/src/main/java/org/wso2/testgrid/core/command/HelpCommand.java
@@ -37,15 +37,13 @@ public class HelpCommand implements Command {
     public void execute() throws CommandExecutionException {
         String ls = System.lineSeparator();
         String usageBuilder = StringUtil.concatStrings(ls,
-                "usage: create-product-testplan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL", ls,
-                "usage: run-testplan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL -t TESTPLAN_PATH -ir " +
-                "INFRA_REPO_PATH -sr SCENARIO_REPO_PATH", ls,
-                "usage: generate-infrastructure-plan -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL -i " +
-                "INFRASTRUCTURE_CONFIG_YAML_PATH", ls,
-                "usage: generate-report -p PRODUCT_NAME -v PRODUCT_VERSION -c CHANNEL", ls,
+                "usage: generate-test-plan -p PRODUCT_NAME -tc TEST_CONFIG_FILE", ls,
+                "usage: run-testplan -p PRODUCT_NAME -ir " +
+                "INFRA_REPO_PATH  -dr DEPLOYMENT_REPO_PATH -sr SCENARIO_REPO_PATH", ls,
+                "usage: generate-report -p PRODUCT_NAME --groupBy GROUPING_COLUMN", ls,
                 "usage: help", ls,
-                "example: sh testgrid.sh create-product-testplan -p wso2is -v 5.3.0 -c LTS", ls,
-                "example: sh testgrid.sh run-testplan -p wso2is -v 5.3.0 -c LTS -t ./my-testplan.yaml", ls);
+                "example: /testgrid generate-test-plan -p wso2is-5.3.0-LTS -tc test-config.yaml", ls,
+                "example: ./testgrid run-testplan -p wso2is-5.3.0-LTS -ir ./Infrastructure  -dr ./Deployment -sr ./Solutions", ls);
         logger.info(usageBuilder);
     }