Pin down prettier
Pin down prettier

In CI, prettier was upgraded from 1.2.2 to 1.4.2 and that caused all of our lint
jobs to fail.  This patch pins down the version of prettier to exactly 1.3.1.
This is the version that is included in the 7-5 deps RPM for tripleo-ui in RDO.

Change-Id: I80d0be7f8ed2271f743f9ad417e6843d9d7a0cf4

knowncitizen/tripleo-ui,knowncitizen/tripleo-ui,knowncitizen/tripleo-ui,knowncitizen/tripleo-ui