Add deploy maven-file command to lftools

Add deploy maven-file command to lftools

The 'deploy maven-file' command uses mvn deploy-file goal
for deploying files to a nexus repository.

Credentials can be provided by settings.xml file in the following way
(order or precedence listed):

    1) User provides the settings file explicitly via -s parameter
    2) User provides the settings file via SETTINGS_FILE envvar
    3) User does not provide the file (default Maven location used)

Jira: releng-160
Change-Id: I0a3af408f70d7d2551a187ec3561b5e609e733d5
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>
Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>