Fix Polymer installed into base environment.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>
4 jobs for feature/separate_ac_land_water in 14 minutes and 29 seconds
Status Job ID Name Coverage
  Test
failed #65176
test_enpt

00:11:55

91.0%
passed #65168
test_styles

00:00:55

passed #65169
test_urls

00:01:38

failed #65167
test_enpt

00:08:21

91.0%
 
Name Stage Failure
failed
test_enpt Test
enpt/version.py                                                        3      0   100%
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TOTAL 2543 235 91%
-----------------------------------------------------------------------------
88 tests run in 656.010 seconds.
1 FAILED (87 tests passed)
make: *** [Makefile:86: nosetests] Error 1
Cleaning up file based variables
ERROR: Job failed: exit code 1