Update OM content type.

Per prometheus/OpenMetrics#79

Signed-off-by: Brian Brazil <[email protected]>

Author: brian-brazil

prometheus_client/exposition.py

@@ -124,7 +124,7 @@ def sample_line(s):
 def choose_encoder(accept_header):
     accept_header = accept_header or ''
     for accepted in accept_header.split(','):
-        if accepted == 'text/openmetrics; version=0.0.1':
+        if accepted == 'application/openmetrics-text; version=0.0.1':
             return (openmetrics.exposition.generate_latest, 
                     openmetrics.exposition.CONTENT_TYPE_LATEST)
     return (generate_latest, CONTENT_TYPE_LATEST)

prometheus_client/openmetrics/exposition.py

@@ -4,7 +4,7 @@
 
 from .. import core
 
-CONTENT_TYPE_LATEST = str('text/openmetrics; version=0.0.1; charset=utf-8')
+CONTENT_TYPE_LATEST = str('application/openmetrics-text; version=0.0.1; charset=utf-8')
 '''Content type of the latest OpenMetrics text format'''
 
 def generate_latest(registry):