feat: Reading mpesa config data from config file instead of environment variables.

[amosmachora]

I have worked on the feature to read mpesa config data for example MPESA_BUSINESS_SHORT_CODE and CONSUMER_KEY from environment varibales allowing us to use different keys for different facilities. I have ignored the config file so that it is not accidentally pushed to Github.

[donaldkibet]

Thanks @amosmachora, LGTM, just one suggestion provide a sample config
e.g

MPESACALLBACKURL: "https://example.com"

Its should just define what goes into the env file and format

[ojwanganto]

Thanks, @amosmachora. I defer to @donaldkibet and @makombe for further reviews.

[amosmachora]

Thanks @amosmachora, LGTM, just one suggestion provide a sample config e.g

MPESACALLBACKURL: "https://example.com"

Its should just define what goes into the env file and format

We only use one callback URL since its our app that receives the data from saf. I have sent a sample config file to both you and @ojwanganto on slack.