Don't eval into the module during precompilation

[ararslan]

This avoids evaluating the symbols from MNE while Julia is precompiling. Seems to fix #4. Closes #5.

[ararslan]

$ tree
.
├── Project.toml
└── src
    └── Thingo.jl

1 directory, 2 files
$ cat src/Thingo.jl 
module Thingo

using PyMNE

end
$ julia --project=.
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.6.0-beta1 (2021-01-08)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

(Thingo) pkg> add PyMNE#aa/precomp
     Cloning git-repo `https://github.com/beacon-biosignals/PyMNE.jl.git`
    Updating git-repo `https://github.com/beacon-biosignals/PyMNE.jl.git`
    Updating registry at `~/.julia/registries/Beacon`
    Updating git-repo `https://github.com/beacon-biosignals/BeaconRegistry.git`
    Updating registry at `~/.julia/registries/General`
    Updating git-repo `https://github.com/JuliaRegistries/General.git`
   Resolving package versions...
Updating `~/Projects/test/Project.toml`
  [6c5003b2] + PyMNE v0.1.0 `https://github.com/beacon-biosignals/PyMNE.jl.git#aa/precomp`
Updating `~/Projects/test/Manifest.toml`
  [8f4d0f93] + Conda v1.5.0
  [682c06a0] + JSON v0.21.1
  [1914dd2f] + MacroTools v0.5.6
  [69de0a69] + Parsers v1.0.15
  [438e738f] + PyCall v1.92.2
  [6c5003b2] + PyMNE v0.1.0 `https://github.com/beacon-biosignals/PyMNE.jl.git#aa/precomp`
  [81def892] + VersionParsing v1.2.0
  [2a0f44e3] + Base64
  [ade2ca70] + Dates
  [8f399da3] + Libdl
  [37e2e46d] + LinearAlgebra
  [d6f4376e] + Markdown
  [a63ad114] + Mmap
  [de0858da] + Printf
  [9a3f8284] + Random
  [9e88b42a] + Serialization
  [4ec0a83e] + Unicode
    Building PyMNE → `~/.julia/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/c30e75022fca80ae7adfb5c1eb4a2ff85fde1554/build.log`
  Progress [========================================>]  2/2
2 dependencies successfully precompiled in 4 seconds (6 already precompiled)

julia> using Thingo

julia> Thingo.PyMNE.io.read_raw_edf
PyObject <function read_raw_edf at 0x7fcd974cfbf8>