include a Metabase icon when we post messages to a slack channel.
include a Metabase icon when we post messages to a slack channel.

blueoceanideas/metabase,zoowii/metabase,Endika/metabase,dashkb/metabase,dashkb/metabase,dashkb/metabase,zoowii/metabase,dashkb/metabase,zoowii/metabase,Endika/metabase,blueoceanideas/metabase,Endika/metabase,Endika/metabase,blueoceanideas/metabase,blueoceanideas/metabase,blueoceanideas/metabase,Endika/metabase,dashkb/metabase,zoowii/metabase,zoowii/metabase