Temporarily revert Debian Stretch builds support, as they fail in Travis.

.travis.yml

@@ -39,7 +39,6 @@ env:
       - OS=ubuntu DIST=zesty
       - OS=debian DIST=wheezy
       - OS=debian DIST=jessie
-      - OS=debian DIST=stretch
       - OS=ubuntu DIST=precise ARCH=i386
       - OS=ubuntu DIST=trusty ARCH=i386
       - OS=ubuntu DIST=xenial ARCH=i386
@@ -47,7 +46,6 @@ env:
       - OS=ubuntu DIST=zesty ARCH=i386
       - OS=debian DIST=wheezy ARCH=i386
       - OS=debian DIST=jessie ARCH=i386
-      - OS=debian DIST=stretch ARCH=i386
 
 matrix:
   exclude:

scripts/buildpack.sh

@@ -57,7 +57,6 @@ distros_x86_64=(
     "ubuntu zesty x86_64"
     "debian wheezy x86_64"
     "debian jessie x86_64"
-    "debian stretch x86_64"
 )
 
 distros_i386=(
@@ -68,7 +67,6 @@ distros_i386=(
     "ubuntu zesty i386"
     "debian wheezy i386"
     "debian jessie i386"
-    "debian stretch i386"
 )
 
 distros_aarch64=(
@@ -79,7 +77,6 @@ distros_aarch64=(
     "ubuntu xenial aarch64"
     "ubuntu yakkety aarch64"
     "debian jessie aarch64"
-    "debian stretch aarch64"
 )
 
 main()