Set up documentation + lint (#121)

- remove some automatically generated stuff not should even be in
repository
- set up lint + Documents.jl in same way it is defined in freshly started projects
- add lint + doctest to after_success so that build pass, these needs to be fixed later
- build is failing on nightly (0.7) but it's ok for release (0.5.2)
- Documenter.jl supports doctests, so this closes least #23
- build system is now on Travis-CI completely, so this closes also #68

docs/deploy.jl

@@ -0,0 +1,9 @@
+# This file is a part of JuliaFEM.
+# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE
+
+using Documenter
+using JuliaFEM
+
+deploydocs(
+    deps = Deps.pip("mkdocs", "python-markdown-math"),
+    repo = "github.com/JuliaFEM/JuliaFEM.jl.git")