dailymotion-cmdline-sample readme minor issues

[Alik Elzin]

3 points feedback on the readme:

1. In the readme exists the following: cd google-oauth-java-client/samples/dailymotion/cmdline-sample:
   instead of dailymotion/cmdline-sample should be dailymotion-cmdline-sample.

2. After cloning the repo and trying to run mvn compile, as instructed in the readme, getting the following error below.
   This is because master is a SNAPSHOT version - nothing in maven remote repos.
   What I did first build (mvn install) the parent (cloned) folder.

alik@alik:~/dev/google-oauth-java-client/samples/dailymotion-cmdline-sample$ mvn compile
[INFO] Scanning for projects...
[INFO] Inspecting build with total of 1 modules...
[INFO] Installing Nexus Staging features:
[INFO]   ... total of 1 executions of maven-deploy-plugin replaced with nexus-staging-maven-plugin
[INFO] 
[INFO] -----< com.google.oauth-client:dailymotion-simple-cmdline-sample >------
[INFO] Building Example for the DailyMotion API using OAuth2. 1.31.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[WARNING] The POM for com.google.oauth-client:google-oauth-client-java6:jar:1.31.1-SNAPSHOT is missing, no dependency information available
[WARNING] The POM for com.google.oauth-client:google-oauth-client-jetty:jar:1.31.1-SNAPSHOT is missing, no dependency information available
[WARNING] The POM for com.google.oauth-client:google-oauth-client:jar:1.31.1-SNAPSHOT is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.639 s
[INFO] Finished at: 2020-09-17T20:09:50Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project dailymotion-simple-cmdline-sample: Could not resolve dependencies for project com.google.oauth-client:dailymotion-simple-cmdline-sample:jar:1.31.1-SNAPSHOT: The following artifacts could not be resolved: com.google.oauth-client:google-oauth-client:jar:1.31.1-SNAPSHOT, com.google.oauth-client:google-oauth-client-java6:jar:1.31.1-SNAPSHOT, com.google.oauth-client:google-oauth-client-jetty:jar:1.31.1-SNAPSHOT: Could not find artifact com.google.oauth-client:google-oauth-client:jar:1.31.1-SNAPSHOT -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException

3. There's a space between exec: and java.
   The command doesn't execute correctly. Deleting the space worked.