Feature/add hl7 support

[rajputd]

This pull request provides an initial version of the redcap_mirth_client. This request should only be reviewed after pull request 5 for the REDCapMirthConnect Client has been approved. This pull request is fairly involved so feel free to contact me if you have any issues.

Creating a test environment:

Install and setup Mirth Connect:

• Install mirth-connect-channel-examples.
• Setup the json_to_hl7_dest_channel_writer channel found in mirth-connect-channel-examples.
• Setup the secure HL7 to MySQL database channel found in mirth-connect-channel-examples.
• Inside the Mirth Connect Administrator go to channels. Copy the channel ID of the HL7 to MySQL database channel. Then go to channels > json_to_hl7_dest_channel_writer > Destinations. Paste the HL7 to MySQL database channel ID into the Channel ID field under the Channel Writer Settings heading.

Install and configure the needed REDCap modules

• Install and set up send_rx. Follow the instructions in the README. Please make sure you use the sites project provided in this pull request. Otherwise, you will need to create a project similar to that one for testing.
• Install the redcap_mirth_client module.
• Enable the redcap_mirth_client on your SendRxPatients project.
• Find the IP address of your Mirth Connect Server as perceived by your VM. To find that IP address ssh into your REDCap VM and run netstat -rn. The only valid Gateway address is the IP address you need.
• Find the internal Mirth Connect Channel ID your send_rx project needs to talk to. This should be the ID of the secure_json_to_hl7_dest_channel_writer you set up earlier.
• Inside the SendRxPatients project, go to the REDCap Mirth Connect Client module configuration menu. Set endpoint ID to 'mirth_connect'. Inside the hl7 end-point field enter the following address: :8002/api/channels/<secure_json_to_hl7 dest_channel_writer channel id>/messages.
• While on the configuration menu enter a json into the 'HL7 json message' field. You can find a sample json payload inside mirth-connect-channel-examples > channels > json_template.json.
• Still, while inside the Mirth Client configuration menu set the username and password fields to the default values specified in the secure_json_to_hl7 dest_channel_writer README.

Review steps:

• On a new or existing Site within the SendRxSites project, enable hl7 as a delivery method.
• Re-login as a prescriber and go to a patient you are able to send prescriptions for. Click send and stay. On the page you should that an hl7 message was send successfully.
• Inside the Mirth Connect Administrator navigate to Dashboard and press the Refresh button under Dashboard Tasks*. If your request succeeded then no errors will appear and it will be forwarded to the database channel. Also the messages received count should be incremented by 1.
• Inside the redcap_mirth_client module's project navigate to the Mirth Logs page to view the request you just sent.