Bump httplib2 from 0.15.0 to 0.18.0

Bumps [httplib2](https://github.com/httplib2/httplib2) from 0.15.0 to 0.18.0.
- [Release notes](https://github.com/httplib2/httplib2/releases)
- [Changelog](https://github.com/httplib2/httplib2/blob/master/CHANGELOG)
- [Commits](httplib2/httplib2@v0.15.0...v0.18.0)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Pipfile

@@ -16,7 +16,7 @@ google-api-python-client = "==1.7.11"
 google-auth = "==1.10.0"
 google-auth-httplib2 = "==0.0.3"
 gspread = "==3.1.0"
-httplib2 = "==0.15.0"
+httplib2 = "==0.18.0"
 idna = "==2.8"
 jmespath = "==0.9.4"
 oauth2client = "==4.1.3"

Pipfile.lock

@@ -1,19 +1,20 @@
+-i https://pypi.org/simple/
 botocore==1.13.46
 cachetools==4.0.0
 certifi==2019.11.28
 chardet==3.0.4
 decorator==4.4.1
 docutils==0.15.2
 google-api-python-client==1.7.11
-google-auth==1.10.0
 google-auth-httplib2==0.0.3
+google-auth==1.10.0
 gspread==3.1.0
-httplib2==0.15.0
+httplib2==0.18.0
 idna==2.8
 jmespath==0.9.4
 oauth2client==4.1.3
-pyasn1==0.4.8
 pyasn1-modules==0.2.7
+pyasn1==0.4.8
 python-dateutil==2.8.1
 requests==2.22.0
 rsa==4.0