navbar: drop old SoC materials

These bloat the navbar list, and are potentially confusing
to applicants looking for the correct page (yes, they have
the year in the title, but it's easy to click the wrong one
by mistake).

Author: peff

Outreachy-2016-May.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: Outreachy May 2016
+navbar: false
 ---
 
 # Outreachy May 2016

SoC-2015-Ideas.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2015 Ideas
+navbar: false
 ---
 
 This is the idea page for Summer of Code 2015 for Git and libgit2.

SoC-2015-Microprojects.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2015 Applicant Microprojects
+navbar: false
 ---
 
 ## Introduction

SoC-2015-Org-Application.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2015 Organization Application
+navbar: false
 ---
 
 This is a draft of git's application to Google's Summer of Code 2015.

SoC-2016-Ideas.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2016 Ideas
+navbar: false
 ---
 
 This is the idea page for Summer of Code 2016 for Git and libgit2.

SoC-2016-Microprojects.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2016 Applicant Microprojects
+navbar: false
 ---
 
 ## Introduction

SoC-2016-Org-Application.md

@@ -1,6 +1,7 @@
 ---
 layout: default
 title: SoC 2016 Organization Application
+navbar: false
 ---
 
 This is a draft of git's application to Google's Summer of Code 2016.