remove message assert as it fails when using interpolation and add SLACK_ATTACHMENTS

[kl4w]

• remove the message assert as it fails when using interpolation, eg message:

SLACK_MESSAGE: "External API ${{CF_BRANCH}} release completed: g.codefresh.io/build/${{CF_BUILD_ID}}"

• Add SLACK_ATTACHMENTS variable

[lrochette]

The default value for IMAGE_VERSION needs to match the step version so 0.0.7

steps/incubating/slack-post-channel/step.yaml

Line 54 in a104b11

"default": "0.0.6",

[lrochette]

This works as expected
You can add this attachment example if you want at line 33 of step.yaml
- description: example-with-attachment workflow: sendSlack: type: slack-post-channel arguments: SLACK_TOKEN: xxxxxx SLACK_CHANNEL: channel1 SLACK_MESSAGE: message SLACK_ATTACHMENTS: > [ { "blocks": [ { "type": "section", "text": { "type": "mrkdwn", "text": "Danny Torrence left the following review for your property:" } }, { "type": "section", "block_id": "section567", "text": { "type": "mrkdwn", "text": "<https://example.com|Overlook Hotel> \n :star: \n Doors had too many axe holes, guest in room 237 was far too rowdy, whole place felt stuck in the 1920s." }, "accessory": { "type": "image", "image_url": "https://is5-ssl.mzstatic.com/image/thumb/Purple3/v4/d3/72/5c/d3725c8f-c642-5d69-1904-aa36e4297885/source/256x256bb.jpg", "alt_text": "Haunted hotel image" } }, { "type": "section", "block_id": "section789", "fields": [ { "type": "mrkdwn", "text": "*Average Rating*\n1.0" } ] } ] } ]