fix failing tests as config function does not exist

Author: nickbarrettjb

src/Eloquent/Builder.php

@@ -25,7 +25,7 @@ protected function getPostgisFields()
     protected function asWKT(GeometryInterface $geometry)
     {
         return $this->getQuery()->raw(
-          sprintf("%s.ST_GeogFromText('%s')", config('postgis.schema'), $geometry->toWKT())
+          sprintf("%s.ST_GeogFromText('%s')", function_exists('config') ? config('postgis.schema') : 'public', $geometry->toWKT())
         );
 
     }

src/Eloquent/PostgisTrait.php

@@ -35,21 +35,21 @@ protected function performInsert(EloquentBuilder $query, array $options = [])
                         case 'GEOMETRY':
                             $this->attributes[$key] = $this->getConnection()->raw(
                               sprintf("%s.ST_GeomFromText('%s', '%d')",
-                                config('postgis.schema'), $value->toWKT(), $attrs['srid'])
+                                function_exists('config') ? config('postgis.schema') : 'public', $value->toWKT(), $attrs['srid'])
                             );
                             break;
                         case 'GEOGRAPHY':
                         default:
                             $this->attributes[$key] = $this->getConnection()->raw(
                               sprintf("%s.ST_GeogFromText('%s')",
-                                config('postgis.schema'), $value->toWKT())
+                              function_exists('config') ? config('postgis.schema') : 'public', $value->toWKT())
                             );
                             break;
                     }
                 } else {
                     $this->attributes[$key] = $this->getConnection()->raw(
                       sprintf("%s.ST_GeomFromText('%s', 4326)",
-                        config('postgis.schema'), $value->toWKT())
+                      function_exists('config') ? config('postgis.schema') : 'public', $value->toWKT())
                     );
                 }
             }