Add OCaml 4.07.0 to test matrix

Author: dra27

.travis.yml

@@ -37,17 +37,20 @@ matrix:
     - os: linux
       env: OCAML_VERSION=4.06.1
       stage: Build
+    - os: linux
+      env: OCAML_VERSION=4.07.0
+      stage: Build
     - os: osx
-      env: OCAML_VERSION=4.06.1 OPAM_TEST=1
+      env: OCAML_VERSION=4.07.0 OPAM_TEST=1
       stage: Test
     - os: osx
       env: OCAML_VERSION=4.03.0
       stage: Test
     - os: linux
-      env: OCAML_VERSION=4.06.1 OPAM_TEST=1
+      env: OCAML_VERSION=4.07.0 OPAM_TEST=1
       stage: Test
     - os: linux
-      env: OCAML_VERSION=4.06.1 OPAM_TEST=1 EXTERNAL_SOLVER=aspcud
+      env: OCAML_VERSION=4.07.0 OPAM_TEST=1 EXTERNAL_SOLVER=aspcud
       stage: Test
     - os: linux
       env: COLD=1