Upgrade dependencies.

requirements/edx/base.txt

@@ -115,7 +115,7 @@ edx-completion==0.1.6
 edx-django-oauth2-provider==1.2.5
 edx-django-release-util==0.3.1
 edx-django-sites-extensions==2.3.1
-edx-drf-extensions==1.2.5
+edx-drf-extensions==1.4.0
 edx-enterprise==0.69.4
 edx-i18n-tools==0.4.5
 edx-milestones==0.1.13
@@ -214,6 +214,7 @@ rules==1.3
 s3transfer==0.1.13        # via boto3
 sailthru-client==2.2.3
 scipy==0.14.0
+semantic-version==2.6.0   # via edx-drf-extensions
 shapely==1.2.16
 shortuuid==0.5.0          # via edx-django-oauth2-provider
 simplejson==3.15.0        # via django-rest-swagger, dogapi, mailsnake, sailthru-client, zendesk

requirements/edx/development.txt

@@ -135,7 +135,7 @@ edx-completion==0.1.6
 edx-django-oauth2-provider==1.2.5
 edx-django-release-util==0.3.1
 edx-django-sites-extensions==2.3.1
-edx-drf-extensions==1.2.5
+edx-drf-extensions==1.4.0
 edx-enterprise==0.69.4
 edx-i18n-tools==0.4.5
 edx-lint==0.5.5
@@ -296,6 +296,7 @@ sailthru-client==2.2.3
 scipy==0.14.0
 scrapy==1.1.2
 selenium==3.12.0
+semantic-version==2.6.0
 service-identity==17.0.0
 shapely==1.2.16
 shortuuid==0.5.0

requirements/edx/testing.txt

@@ -130,7 +130,7 @@ edx-completion==0.1.6
 edx-django-oauth2-provider==1.2.5
 edx-django-release-util==0.3.1
 edx-django-sites-extensions==2.3.1
-edx-drf-extensions==1.2.5
+edx-drf-extensions==1.4.0
 edx-enterprise==0.69.4
 edx-i18n-tools==0.4.5
 edx-lint==0.5.5
@@ -285,6 +285,7 @@ sailthru-client==2.2.3
 scipy==0.14.0
 scrapy==1.1.2             # via pa11ycrawler
 selenium==3.12.0
+semantic-version==2.6.0
 service-identity==17.0.0  # via scrapy
 shapely==1.2.16
 shortuuid==0.5.0