Merge branch 'master' into newbust

lib/dialects/mysql/query-generator.js

@@ -377,7 +377,7 @@ module.exports = (function() {
       }, options || {})
 
       return Utils._.compact([
-        "CREATE", options.indicesType, "INDEX", options.indexName,
+        "CREATE", options.indicesType, "INDEX IF NOT EXISTS", options.indexName,
         (options.indexType ? ('USING ' + options.indexType) : undefined),
         "ON", tableName, '(' + transformedAttributes.join(', ') + ')',
         (options.parser ? "WITH PARSER " + options.parser : undefined)

lib/dialects/sqlite/query-generator.js

@@ -378,7 +378,7 @@ module.exports = (function() {
     },
 
     removeIndexQuery: function(tableName, indexNameOrAttributes) {
-      var sql       = "DROP INDEX <%= indexName %>"
+      var sql       = "DROP INDEX IF EXISTS <%= indexName %>"
         , indexName = indexNameOrAttributes
 
       if (typeof indexName !== 'string') {