improve the slack icon that gets used in message posts.
improve the slack icon that gets used in message posts.

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