Upgrade Jenkins plugins

Update build-timeout to 1.18
Update credentials to 2.1.10
Update git to 3.0.1
Update git client to 2.1.0 (bumps jgit from 3 to 4.)
Update git server to 1.7.
Update github to 1.24.0
Update github-api to 1.80
Update github-branch-source to 1.10.1
Update github-oauth to 0.25
Update github-organization-folder to 1.5
Update ssh-slaves to 1.12

Change-Id: I7b450db78d4f00a1dc604dfc0d5f9deb35b216c0
diff --git a/jenkins-docker/master/plugins.txt b/jenkins-docker/master/plugins.txt
index 2b6c6d3..26ce9c3 100644
--- a/jenkins-docker/master/plugins.txt
+++ b/jenkins-docker/master/plugins.txt
@@ -2,21 +2,21 @@
 antisamy-markup-formatter:1.3
 branch-api:1.8
 build-flow-plugin:0.19
-build-timeout:1.16
+build-timeout:1.18
 cloudbees-folder:5.11
-credentials:2.0.6
+credentials:2.1.10
 docker-plugin:0.16.2
 durable-task:1.10
 embeddable-build-status:1.9
 envinject:1.92.1
-git:2.4.4
-git-client:1.19.6
-github:1.19.1
-github-api:1.75
-github-branch-source:1.7
-github-oauth:0.24
-github-organization-folder:1.3
-git-server:1.6
+git:3.0.1
+git-client:2.1.0
+github:1.24.0
+github-api:1.80
+github-branch-source:1.10.1
+github-oauth:0.25
+github-organization-folder:1.5
+git-server:1.7
 greenballs:1.15
 groovy-postbuild:2.3.1
 handlebars:1.1.1
@@ -39,7 +39,7 @@
 scm-api:1.2
 script-security:1.19
 ssh-credentials:1.12
-ssh-slaves:1.11
+ssh-slaves:1.12
 structs:1.1
 token-macro:1.12.1
 timestamper:1.8.2