Properly deprecate -G option, don't just remove it.
### Description of Issue/Question

The `-G` option was removed in #945. However, we should still allow the -G option to work by providing a way for it to still work as-is with a warning message that it will be removed in the near future. 

We should make sure this gets fixed before we release a new stable version of the bootstrap script. #945 is not in the current stable release, and we don't want to remove that functionality from underneath people without proper warning and time for people to update their script usage, wrappers, and salt-cloud configs.

ping @vutny and @The-Loeki 

diff --git a/README.rst b/README.rst
index 33e7763..951f9e0 100644
--- a/README.rst
+++ b/README.rst
@@ -66,7 +66,7 @@ If you want to install a specific release version (based on the Git tags):
 .. code:: console
 
   curl -o bootstrap_salt.sh -L https://bootstrap.saltstack.com
-  sudo sh bootstrap_salt.sh git v2015.8.8
+  sudo sh bootstrap_salt.sh git v2016.3.2
 
 To install a specific branch from a Git fork:
 
@@ -88,7 +88,7 @@ If your host has Internet access only via HTTP proxy:
 
   PROXY='http://user:password@myproxy.example.com:3128'
   curl -o bootstrap_salt.sh -L -x "$PROXY" https://bootstrap.saltstack.com
-  sudo sh bootstrap_salt.sh -G -H "$PROXY" git
+  sudo sh bootstrap_salt.sh -H "$PROXY" git
 
 
 Install using wget
@@ -106,7 +106,7 @@ Installing a specific version from git using ``wget``:
 .. code:: console
 
   wget -O bootstrap_salt.sh https://bootstrap.saltstack.com
-  sudo sh bootstrap_salt.sh -P git v2015.8.7
+  sudo sh bootstrap_salt.sh -P git v2015.8.11
 
 .. note::
 
@@ -548,8 +548,8 @@ Salt is ready and working in the Docker container with Minion authenticated on M
 .. _`pre-accepted Minion key`: https://docs.saltstack.com/en/latest/topics/tutorials/preseed_key.html
 
 
-.. vim: fenc=utf-8 spell spl=en cc=100 tw=99 fo=want sts=2 sw=2 et
-
 .. |windows_build|  image:: https://ci.appveyor.com/api/projects/status/github/saltstack/salt-bootstrap?branch=develop&svg=true
     :target: https://ci.appveyor.com/project/saltstack-public/salt-bootstrap
     :alt: Build status of the develop branch on Windows
+
+.. vim: fenc=utf-8 spell spl=en cc=100 tw=99 fo=want sts=2 sw=2 et
diff --git a/bootstrap-salt.sh b/bootstrap-salt.sh
index 4b94836..e9c4a41 100755
--- a/bootstrap-salt.sh
+++ b/bootstrap-salt.sh
@@ -193,7 +193,7 @@ __check_config_dir() {
 #----------------------------------------------------------------------------------------------------------------------
 _KEEP_TEMP_FILES=${BS_KEEP_TEMP_FILES:-$BS_FALSE}
 _TEMP_CONFIG_DIR="null"
-_SALTSTACK_REPO_URL="git://github.com/saltstack/salt.git"
+_SALTSTACK_REPO_URL="https://github.com/saltstack/salt.git"
 _SALT_REPO_URL=${_SALTSTACK_REPO_URL}
 _DOWNSTREAM_PKG_REPO=$BS_FALSE
 _TEMP_KEYS_DIR="null"
@@ -280,10 +280,6 @@ __usage() {
     -D  Show debug output
     -c  Temporary configuration directory
     -g  Salt Git repository URL. Default: ${_SALTSTACK_REPO_URL}
-    -G  Instead of cloning from ${_SALTSTACK_REPO_URL}, clone from
-        https://${_SALTSTACK_REPO_URL#*://}
-        (usually necessary on systems which have the regular git protocol port
-        blocked, where https usually is not)
     -w  Install packages from downstream package repository rather than
         upstream, saltstack package repository. This is currently only
         implemented for SUSE.
@@ -360,7 +356,7 @@ EOT
 }   # ----------  end of function __usage  ----------
 
 
-while getopts ":hvnDc:Gg:wk:s:MSNXCPFUKIA:i:Lp:dH:ZbflV:J:j:rR:aq" opt
+while getopts ":hvnDc:g:wk:s:MSNXCPFUKIA:i:Lp:dH:ZbflV:J:j:rR:aq" opt
 do
   case "${opt}" in
 
@@ -383,14 +379,6 @@ do
 
     g )  _SALT_REPO_URL=$OPTARG                         ;;
 
-    G )  if [ "${_SALT_REPO_URL}" = "${_SALTSTACK_REPO_URL}" ]; then
-             _SALTSTACK_REPO_URL="https://github.com/saltstack/salt.git"
-             _SALT_REPO_URL=${_SALTSTACK_REPO_URL}
-         else
-             _SALTSTACK_REPO_URL="https://github.com/saltstack/salt.git"
-         fi
-         ;;
-
     w )  _DOWNSTREAM_PKG_REPO=$BS_TRUE                  ;;
 
     k )  _TEMP_KEYS_DIR="$OPTARG"
@@ -1553,8 +1541,7 @@ __git_clone_and_checkout() {
             # shellcheck disable=SC2164
             cd "${_SALT_GIT_CHECKOUT_DIR}"
 
-            if ! echo "$_SALT_REPO_URL" | \
-                grep -q -x '\(\(git\|https\)://github\.com/\|git@github\.com:\)saltstack/salt\.git'; then
+            if ! echo "$_SALT_REPO_URL" | grep -q -F -w "${_SALTSTACK_REPO_URL#*://}"; then
                 # We need to add the saltstack repository as a remote and fetch tags for proper versioning
                 echoinfo "Adding SaltStack's Salt repository as a remote"
                 git remote add upstream "$_SALTSTACK_REPO_URL" || return 1
diff --git a/tests/bootstrap/test_install.py b/tests/bootstrap/test_install.py
index 0b34ec8..3195c2e 100644
--- a/tests/bootstrap/test_install.py
+++ b/tests/bootstrap/test_install.py
@@ -605,7 +605,7 @@ class InstallationTestCase(BootstrapTestCase):
             0,
             self.run_script(
                 script=None,
-                args=('git', 'clone', 'git://github.com/saltstack/salt.git'),
+                args=('git', 'clone', 'https://github.com/saltstack/salt.git'),
                 cwd='/tmp/git',
                 timeout=15 * 60,
                 stream_stds=True
['tests/bootstrap/test_install.py', 'bootstrap-salt.sh', 'README.rst']