moved dependency Documenter.jl to extras,

added corresponding line to .travis.yml,
added "Documenter" to targets,
and rebased, in order to have a chance that the tests with Julia 1.1 pass

.travis.yml

@@ -26,6 +26,7 @@ branches:
 
 install:
   # install some optional dependencies for our tests
+  - JULIA_PROJECT= julia -e 'import Pkg ; Pkg.add("Documenter")'
   - JULIA_PROJECT= julia -e 'import Pkg ; Pkg.add("Nemo")'
   - JULIA_PROJECT= julia -e 'import Pkg ; Pkg.add("Primes")'
   - JULIA_PROJECT= julia -e 'import Pkg ; Pkg.add("LinearAlgebra")'

Project.toml

@@ -4,7 +4,6 @@ authors = ["Thomas Breuer <[email protected]>", "Sebastian Gutsche <gutsch
 version = "0.2.6"
 
 [deps]
-Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
@@ -13,7 +12,8 @@ REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 julia = "1.1"
 
 [extras]
+Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Test","Documenter"]