add "--fm" option to support FastModels in mbedhtrun

[jamesbeyond]

Description

In order to support FastModels in mbed testing framework, an extra option "--fm" been added to mbedhtrun.

This option will allow mbedhtrun hooks up with fm_agent module, and run tests over FastModels

The command line format of the --fm is following the RaaS_Client "--grm" convention

Details

• "--fm" been added to htrun
• user could use mbedhtrun -m \ --fm -f
  • e.g. mbedhtrun -m FVP_MSP2_M3 --fm DEFAULT -f ticker.elf
• conn_primitive_fastmodel class been added, allow communication between htrun and fm_agent

This PR is related with other PRs regarding to FastModel support in testing framework ARMmbed/greentea#270 ARMmbed/mbed-ls#345

CC. @theotherjimmy @studavekar @bridadan @bulislaw

[coveralls]

Coverage decreased (-0.04%) to 49.01% when pulling b7ff09103f2541853ecc90d6e0a5cb7cf738527f on jamesbeyond:fastmodel_client into 525eda7ddd5854480ee91c48ccee9194a5efd4b9 on ARMmbed:master.

[coveralls]

Coverage decreased (-0.2%) to 48.851% when pulling cbe2f30e59add1ccab2a586c9e6cc241ccc0f995 on jamesbeyond:fastmodel_client into 525eda7ddd5854480ee91c48ccee9194a5efd4b9 on ARMmbed:master.

[jamesbeyond]

Changed --srm to --fm Could you review again please? @theotherjimmy @bridadan

[jamesbeyond]

Hi @bridadan @theotherjimmy Both Htrun and Greentea got updated. The "--fm" option only shows only if it detects fm_agent module installed. Also the README got updated as well.