dplyr translations for odbc

[jonkeane]

#151 enabled tests for some dplyr translations, however odbc backends will not work because the class of the mock connection doesn't inherit from the adhoc classes that odbc generates and we get the following error:

Error (test-dbi-generic-integration.R:361:13): dplyr + a regex odbc
Error: str_detect() is not available in this SQL variant
Backtrace:
  1. `%>%`(...) test-dbi-generic-integration.R:361:12
 17. dbplyr:::str_detect(name, "\\.")