fix doc build failure (#35)

* minor doc dep update

* rm unnecessary dep

* add distributions random linearalgebra to docs env

Author: zuhengxu

docs/Project.toml

@@ -1,3 +1,9 @@
 [deps]
+Bijectors = "76274a88-744f-5084-9051-94815aaf08c4"
+Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
+Flux = "587475ba-b771-5e3f-ad9e-33799f191a9c"
+Functors = "d9f16b24-f501-4c13-a1f2-28368ffc5196"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 NormalizingFlows = "50e4474d-9f12-44b7-af7a-91ab30ff6256"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"