convert real to rational

[GiggleLiu]

julia> zxd = ZXDiagram(4);

julia> push_gate!(zxd, Val(:X), 3, 0.5);

julia> push_gate!(zxd, Val(:X), 3, 0.3);

julia> push_gate!(zxd, Val(:X), 3, 1/3)
ZX-diagram with 11 vertices and 7 multiple edges:
(S_1{input} <-1-> S_2{output})
(S_3{input} <-1-> S_4{output})
(S_5{input} <-1-> S_9{phase = 1//2⋅π})
(S_6{output} <-1-> S_11{phase = 1//3⋅π})
(S_7{input} <-1-> S_8{output})
(S_9{phase = 1//2⋅π} <-1-> S_10{phase = 3//10⋅π})
(S_10{phase = 3//10⋅π} <-1-> S_11{phase = 1//3⋅π})

[codecov[bot]]

Codecov Report

Merging #51 into master will increase coverage by 0.02%. The diff coverage is 93.33%.

@@            Coverage Diff             @@
##           master      #51      +/-   ##
==========================================
+ Coverage   89.95%   89.98%   +0.02%     
==========================================
  Files          13       13              
  Lines        1225     1238      +13     
==========================================
+ Hits         1102     1114      +12     
- Misses        123      124       +1     

Impacted Files	Coverage Δ
src/zx_diagram.jl	96.86% <93.33%> (-0.29%)	:arrow_down:

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[Roger-luo]

I'm wondering what if the phase is not something like 0.5, but something like 0.31491304324324423423, will it still get converted? If so, I think call this function explicitly could be better, or have an option to use this.