CDB-3568 fixed proper vis author url
remove_column replaced by drop_column in last migration files
Merge pull request #620 from CartoDB/CDB-3568

CDB-3568 fixed proper vis author url
Upgraded extension version to 0.3.1
Merge pull request #622 from CartoDB/CDB-3536

[CDB-3536] Upgraded extension version to 0.3.1
Merge branch 'master' into CDB-3537
CDB-3537 #resolve - my tables/visualizations section added
Merge branch 'CDB-3537' of github.com:CartoDB/cartodb into CDB-3537